,transcriber's ,note3 ,italic text is denoted by underscores4 ,,practical ,,lithography ,illustration3 ,,alois ,,senefelder4 ,the ,inventor of ,lithography4 ,born #agha--;,died #ahcd4 ,,practical ,,lithography ,,by ,,alfred ,,seymour ,,author ,,of ,,modern ,,printing ,,inks ,,and ,,colour ,,printing ,,rule ,,of ,,thumb ,,in ,,the ,,workshop ,,some ,,work-,a-,,day ,,notions ,,etc41 ,,etc4 ,,with ,,frontispiece ,,and ,,thirty-,,three ,,illustrations ,,london ,,scott1 ,,greenwood ,,co4 #ai ,,ludgate ,,hill1 ,e4,c4 ,,new ,,york ,d4 ,,van ,,nostrand ,,company #bc ,,murray ,,street #aijc ,all ,rights remain with ,scott1 ,greenwood ,co4 ,,introduction ,alois ,senefelder never benefited much by his discovery of the elementary principles of lithography1 but none of those to whom it has given profitable occupation will remember without some feeling the patient and persistent efforts of the struggling actor and dramatist who1 only after the greatest sacrifices and hardships1 laid the germ of this splendid development1 and watched and guarded its growth4 ,there is one characteristic feature of the discovery of lithography for which ,senefelder ought to receive the fullest credit4 ,unlike other discoveries of industrial and scientific value1 there can be no doubt whatever as to its origin4 ,senefelder's claim has never been disputed1 yet the payment of a debt of gratitude to the fact is easily overlooked when the wheel of history has made another turn4 ,it has been again and again suggested that the blighting influences of ,commercialism have robbed lithography of many of its traditional features and a few1 at least1 of its best and most artistic qualities as a reproductive art4 ,this same commercial spirit1 however1 has inspired and encouraged a charming variety of effect both in colour and design1 and lithography of to-day1 in almost every form of its manifestation1 is infinitely more attractive and capable of considerably more expressive power than could ever have been hoped for before commercial utility and value demanded a full recognition4 ,pleasing and harmonious effects1 which are almost invariably sought after in lithography1 need not be inartistic2 and it is quite possible for the technique of the lithographic draughtsman to translate original work without a serious depreciation of its pictorial and artistic value4 ,while expressing a sincere hope that this volume may be of considerable assistance to his fellow-craftsmen1 the writer wishes to emphasise the fact that resourcefulness and intelligent application are faculties which may be encouraged and amplified but cannot be imparted even by volumes of text4 ,a mere formal acknowledgment of assistance cordially rendered by the editors of the ,british ,printer and ,the ,caxton ,magazine and ,press1 ,messrs4 ,penrose ,co41 and other firms whose blocks are prim facie evidences of their interest1 does not adequately express the appreciation with which it has been accepted and made use of4 ,a4 ,s4 ,,london1 ,december #aijc4 ,,contents ,,page ,,introduction v ,,list ,,of ,,illustrations xi ,,chapter ,i ,,elementary ,,details ,concerning ,stones--,character and ,texture--,some ,simple ,elements--,preparation of ,stones--,planing and ,levelling-- ,grinding ,grained ,stones--,descriptive ,treatment-- ,american ,method #a-g ,,chapter ,,ii ,,lithographic ,,transfer ,,inks ,various ,forms--,distinguishing ,features--,formul--,writing ,transfer ,ink--,stone-to-stone ,transfer ,ink--,copperplate ,transfer ,ink--,a ,modification #h-aa ,,chapter ,,iii ,,lithographic ,,transfer ,,papers ,essential ,features--,varnish ,transfer ,paper--,damp-stone ,transfer ,paper--,french ,transparent ,transfer ,paper-- ,copperplate ,transfer ,paper--,an ,alternative ,recipe-- ,granulated ,papers--,photo-litho ,transfer ,paper #ab-af ,,chapter ,,iv ,,copperplate ,,transfer ,,printing ,the ,copperplate ,press--,the ,operation--,charging the ,engraved ,plate--,cleaning-off and ,polishing--,making the ,impression--,useful ,notions #ag-ai ,,chapter ,v ,,the ,,lithographic ,,press ,mechanical ,principles--,constructive ,details--,scraper-- ,tympan--,practical ,suggestions--,elastic ,bedding #bj-bc ,,chapter ,,vi ,,lithographic ,,press ,,work ,preparing the ,design--,treatment of an ,ink ,drawing--,chalk ,drawings--,alterations--,value of ,impressions--,offsets--,the ,lithographic ,hand-roller--,proving--,registration--, general ,features--,transferring--,a ,commercial ,necessity-- ,arrangement--,choice of ,paper--,transference to ,stone-- ,preparing the ,forme #bd-cc ,,chapter ,,vii ,,machine ,,printing ,the ,printing ,machine--,the ,halligan--,some ,mechanical ,phases--,speed--,pressure--,levelling the ,stones--,cylinder ,brake--,inking ,rollers--,damping #cd-dj ,,chapter ,,viii ,,machine ,,printing--continued ,register--,atmospheric ,conditions--,the ,key--,the ,gripper-- ,starting the ,machine--,fixing the ,stone--,strength of ,colour--,grit--,making ,ready--,regulation of ,speed #da-df ,,chapter ,,ix ,,lithographic ,,colour ,,printing ,a ,commercial ,value--,peculiar ,features--,colour ,sequence-- ,controlling ,elements--,a ,question of ,register--,suitable ,paper #dg-ea ,,chapter ,x ,,lithographic ,,colour ,,printing--continued ,printing ,inks--,varnish--,reducing ,medium--,relative ,values--,some ,useful ,hints--,bronze ,blue--,vermilion--,ink ,mixing--,ceramic ,transfers--,colour ,transparencies #eb-ef ,,chapter ,,xi ,,substitutes ,,for ,,lithographic ,,stones ,metal ,plates--,preparation--,manipulation--,d escriptive ,details--,machine ,printing--,the ,printing ,bed--,rotary ,printing ,machine #eg-ff ,,chapter ,,xii ,,tin-,,plate ,,printing ,its ,evolution--,transfer and ,direct ,transfer ,printing-- ,the ,coated ,paper--,reversed ,designs--,sequence of ,printing--,printing ,inks--,purity of ,tone--,drying #fg-ga ,,chapter ,,xiii ,,tin-,,plate ,,printing--continued ,direct ,tin ,printing--,the ,machine--,peculiarities of ,impression--,cylinder ,covering--,colour ,sequence--,printing ,inks--,drying ,racks--,air-drying versus ,stoving #gb-gi ,,chapter ,,xiv ,,tin-,,plate ,,decoration ,suitable ,designs--,a ,variety of ,effects--,gold ,lacquer-- ,super-position of ,colours--,embossed ,effects--,embossing ,plates--,lacquers #hj-hc ,,chapter ,,xv ,,photo-,,lithography ,early ,experiments--,an ,analysis--,the ,direct ,process-- ,transfer ,process--,line and ,half-tone--,some ,difficulties-- ,a ,natural ,grain--,ink ,photo-screen ,effects--,essential ,features #hd-hh ,,chapter ,,xvi ,,photo-,,lithography--continued ,the ,copy--,gradations of ,tone--,scraper ,boards--,description and ,effect--,shading ,mediums--,crayon ,drawings--,half-tone ,copy #hi-ie ,,chapter ,,xvii ,,photo-,,lithography--continued ,a ,copying ,table--,exposure--,illumination--,photo -litho ,transfers--,the ,paper--,printing--,developing--,a ,direct ,process #if-aja ,,index #ajb-ajd ,,illustrations ,,page ,,alois ,,senefelder ,frontispiece ,,stone-,,planing ,,machine #d ,,stone-,,polishing ,,machine #e ,,copperplate ,,press #ag ,,hot ,,plate #ah ,,lithographic ,,press #ba ,,details ,,of ,,lithographic ,,press #bb ,,lithographic ,,hand ,,press #bc ,,lithographic ,,hand ,,roller #bh ,,register ,,lines #cj ,,arrangement ,,of ,,transfers #cb ,,transferring ,,board #cb ,,lithographic ,,printing ,,machine #ce ,,halligan ,,machine #cf ,,pressure ,,mechanism #ch ,,inking ,,rollers #ci ,,damping ,,rollers #dj ,,gripper #db ,,trimmed ,,edges #dc ,,counter ,,shafting #dd ,,motor ,,driving #de ,,plate-,,graining ,,machine #ei1 #fj ,,plate ,,bed #fb ,,aluminium ,,rotary ,,machine #fc ,,aluminium ,,rotary ,,section #ff ,,tin-,,plate ,,printing ,,machine #gc ,,tin-,,plate ,,racks #gh1 #gi ,,method ,,of ,,stacking ,,plates #gi ,,scraper ,,board ,,work #ia ,,scraper ,,board ,,textures #ic ,,photographic ,,copying ,,board #ig ,,practical ,,lithography ,,chapter ,i ,,elementary ,,details ,concerning ,stones--,character and ,texture--,some ,simple ,elements--,preparation of ,stones--,planing and ,levelling-- ,grinding ,grained ,stones--,descriptive ,treatment--,american ,method4 ,there are a vast number of details in connection with lithography and lithographic printing which are indisputably elementary in their character4 ,it would be impossible1 however1 to regard them as non-essential1 and a just appreciation of their value and influence must of necessity enter into any comprehensive exposition of the craft4 ,stone as a printing medium4--,the value of the ,bavarian limestone was one of those fortunate discoveries which tended to materialise lithography as a graphic art1 and may even be regarded as a fundamental principle1 the practical value of which is only equalled by its far-reaching effects4 ,other printing surfaces have been discovered and developed1 with more or less substantial results1 yet without depreciating their merits1 it will be but a fair recognition to concede the premier position to the ,solenhofen and other limestones of a like nature4 ,the homogeneity and porosity of these stones render them peculiarly suitable for lithographic purposes1 and it undoubtedly reflects a vast amount of credit upon ,senefelder that even at the outset he should select a medium so well adapted and in every way so eminently suitable for graphic reproduction4 ,i have already1 and almost inadvertently1 indicated the peculiar value of the ,bavarian stone1 for homogeneity and porosity of texture are absolutely essential properties1 and upon these is based almost every theory which has assisted in the development of this craft4 ,these properties1 in conjunction with a suitable greasy pigment1 provide the requisite materials for that cause and effect which require and compel consideration4 ,the simple elements of lithography may be very briefly described1 and in this direction at least we must follow certain well-defined lines which may be regarded as well-worn ruts1 the consideration of which offers little that is new4 ,a brief review of the theories of chemical and mechanical affinities is best calculated to impress upon the mind the elementary principles of the lithographer's art4 ,the penetrative power of a greasy pigment1 together with the porous nature of the litho-stone1 may be regarded as the cause by which the lithographer produces as an effect a design or impression which1 to some extent1 enters into the texture of the stone--the homogeneity of which checks any tendency to spread4 ,this fatty matter may be applied in one or two ways1 either as a transfer from some other printing surface1 or as a direct drawing with pen1 brush1 or crayon4 ,the first question for consideration will be the initial preparation of the litho-stones4 ,these preparatory operations--which have for their object the levelling1 polishing1 and cleaning of the stones--were at one time entirely performed by hand labour1 but are now accomplished with much greater facility and in a more effective manner by machinery4 ,the importance of each individual operation will be more readily appreciated when once its purpose is clearly understood4 ,a litho-stone having a perfectly level surface is necessary in order to enable the printer to secure a firm and uniform pressure over the whole design when printing therefrom4 ,a smooth1 polished surface will readily receive the finest designs1 and retain all their original characteristics4 ,a clean surface is an absolute necessity1 i4e4 a chemically clean surface free from grease or any foreign matter which would be likely to enter into the texture of the stone and by so doing injure any greasy drawing or transfer which might be made thereon4 ,these are simple1 elementary principles1 and as such are probably familiar to every reader1 but the frequent result of familiarity is a dangerous tendency to under-estimate the importance of everyday causes and effects4 ,if1 therefore1 such a reference as the above to common details serves to convey some intelligent idea of their place and true value1 then no apology whatever will be necessary for their insertion in this volume4 ,it has already been stated that1 in the preparation of litho-stones1 the superseding of hand labour by machinery has effected considerable and important changes4 ,several machines1 all of more or less practical value1 have been introduced to the trade4 ,one of the more recent developments1 a stone-planing machine1 possesses many features of real merit 7,fig4 #a74 ,the stone is securely fixed on a perfectly true bed and passes slowly to and fro beneath the blades of powerful cutting knives4 ,these blades are arranged in an inverted ,v-shape and locked in an oscillating framework4 ,by an automatic action they are almost imperceptibly lowered at each traverse of the machine1 when they lightly cut away the surface of the stone until the old work is completely removed and a smooth level face is assured4 ,the chief objection to this type of machine is that in course of time the knives become worn and slightly irregular1 and it is but reasonable to suppose that when a number of small stones have been operated upon and immediately afterwards a full-sized stone is planed1 such irregularities will be very pronounced and detrimental4 ,illustration3 ,,fig4 #a4 ,many machines have been designed on the simple grinding principle1 but one type differs from its contemporaries and offers several distinct advantages over them 7,fig4 #b74 ,this machine is constructed on hand-polishing lines1 i4e4 the movements are to some extent mechanical arrangements of hand-polishing principles4 ,the size of stone makes no difference whatever1 and the results are in the main uniform and satisfactory4 ,the inconveniently sharp edges1 such as are produced by the planing machine1 are unknown1--the wear and tear on the stone is perceptibly lessened1 and the power required to drive such a machine is not by any means a serious matter4 ,when a planing machine does not enter into the operation1 and grinding by hand is therefore necessary1 sharp1 clean sand should be used as a grinding medium4 ,to secure some degree of uniformity in the grain1 and at the same time remove all the larger particles of grit1 pass the sand first through a fine sieve4 ,the harder qualities of sand have1 of course1 the greatest cutting power1 and therefore are the most suitable for this purpose4 ,illustration3 ,,fig4 #b4 ,when hand-grinding is resorted to1 a continuous elliptical motion of one stone over the other with a slight twist from the wrist will prove most effective4 ,to finish the grinding1 and as far as possible remove the deeper sand scratches1 work off the sand in the form of a sludge4 ,unless this operation is carefully and patiently performed1 scratches of considerable depth may appear on various parts of the stone's surface4 ,these1 in the subsequent polishing1 may offer a strong temptation to the operator to work over one part of the stone more than another1 so as to effect the removal of such scratches with greater rapidity4 ,the almost certain result of this would be an uneven surface1 which would in many ways prove troublesome to the printer4 ,the graining of stones4--,this is a matter concerning the preparation of stones which must not be overlooked4 ,the introduction of shading mediums and other contrivances of a similar character has considerably minimised the importance of the grained stone1 inasmuch as it cannot now be regarded as an indispensable feature of lithography4 ,it is1 however1 still of inestimable value1 and will probably always find a place and purpose in the practice of lithography1 despite its depreciation owing to present-day limitations4 ,recognising1 then1 the possibility of its retention1 at least for some time to come1 as a suitable printing surface upon which the lithographic draughtsman can work with undoubted facility of execution and effect1 we must perforce include a brief description of its preparation in this chapter4 ,first of all1 level the stone and to some extent polish it1 after which the graining may be proceeded with4 ,a glass muller about #f or #g inches in diameter makes an excellent grainer4 ,failing this1 a handy substitute will be found in the form of a small litho-stone1 hard in texture1 and with a smooth1 level surface4 ,use as a graining medium sharp1 clean silver sand only1 passing it carefully through a sieve according to the size or depth of the grain required4 ,sprinkle a little of this sand uniformly over the stone under treatment1 together with a few drops of clean water4 ,with a continuous circular movement pass the graining muller from end to end of the stone1 exerting a firm and uniform pressure4 ,repeat this operation again and again1 adding sand and water as required4 ,considerable time coupled with intelligent application will be necessary to carry out this work successfully4 ,should the sand become too much worn before its renewal the grain will in proportion lose its tooth or sharpness4 ,on the other hand lies the danger of producing a grain which is too harsh or pronounced4 ,therefore much depends upon the skill and judgment of the operator4 ,a safe plan is to ascertain the progress at any time when a satisfactory result might be reasonably expected4 ,the best way to accomplish this is by washing from the face of the stone any accumulation of sand1 and drying it1 so that a test can be made with the actual grade of crayon to be used in the subsequent drawing4 ,a powerful current of clean1 cold water affords the best means for removing every trace of sand from the finished stone1 and will leave it in a condition of almost complete readiness for the draughtsman2 a good drying is then all that is necessary4 ,good results have been claimed for a method of graining which was introduced by the ,americans a few years ago4 ,in this process the grain is produced by sprinkling the surface of the stone with sand and rolling it with small glass balls4 ,these balls having a limited area in which to work exert a continuous cutting power without any tendency to produce scratches4 ,some mechanical arrangement is necessary to impart this continuous rolling movement to the glass balls and to maintain a uniform speed4 ,it is quite easy to understand that with such a process1 carried out under favourable conditions1 very fine results might be produced with great rapidity4 ,,chapter ,,ii ,,lithographic ,,transfer ,,inks ,various ,forms--,distinguishing ,features--,formul--,writing ,transfer ,ink--,stone-to-stone ,transfer ,ink--,copperplate ,transfer ,ink--,a ,modification4 ,given a perfectly clean and smooth polished stone as described in the previous chapter1 the next important point is the composition of the fatty matter wherewith a design or drawing is applied4 ,as already stated1 the active principle in any suitable transfer medium of this character is invariably the same1 no matter what form its composition takes4 ,for applying with pen or brush it must possess soluble properties1 and of necessity be reduced to a liquid form4 ,such soluble properties1 however1 must not interfere with its fatty properties1 these latter being essential features4 ,in crayon or chalk drawing the composition must be employed in a concrete form1 as a crayon1 the hardness and texture of which will be controlled 7#a7 by the character of the work to be carried out2 7#b7 by the character of surface to be operated upon4 ,transfers from other printing surfaces can only be made when the composition used is in the form of a pigment1 and reduced to a convenient working consistency4 ,these1 then1 comprise the varieties of transfer mediums which are likely to be required in most phases of commercial lithography4 ,others are1 of course1 employed for specific purposes and under peculiar conditions2 but these1 again1 are more or less modifications of existing formul1 prepared to meet particular requirements4 ,the ink used for transferring impressions from one printing surface to another1 e4g41 the re-transferring of work from stone to stone1 may with a very slight alteration serve for type to stone transfer2 but a considerable departure must be effected to produce a satisfactory photo-litho transfer ink1 while a composition of a peculiarly distinctive character will be requisite for the successful production of transfers from copperplate engravings1 as well as for a transfer ink for writing and drawing on stone or transfer paper4 ,this writing transfer ink must be soluble in water1 yet without becoming slimy2 otherwise it will not work freely with the pen or brush4 ,it must also dry quickly1 and without any tendency to smear4 ,a plate transfer ink must neither melt nor drag when applied to the hot plate4 ,it must1 of course1 soften sufficiently to fill in the lines of the engraving1 and should so harden as it cools that it cannot easily be dragged away during the cleaning and polishing operations4 ,see ,chap4 ,,iv4 page #ai4 ,each and all of the above inks must be excessively greasy and penetrative1 but without having the slightest tendency to spread superficially4 ,the ingredients and methods of preparation specified in the succeeding paragraphs are not given as standard formul1 but in corroboration of statements made1 and as practical illustrations of the character and purpose of transfer inks and compositions generally4 ,transfer ink4--,writing transfer ink1 for writing or drawing on stone or transfer paper1 may consist of equal quantities of3-- ,castile soap1 ,wax1 ,tallow1 ,shellac1 with the addition of carbon black or black printing ink as a colouring matter4 ,another reliable formula is3-- ,soap #d parts ,tallow #c parts ,wax #f parts ,shellac #d parts ,carbon black #a parts ,whichever formula is adopted the method of preparation is the same combination4 ,free the soap from all moisture by drying1 and thus facilitate its combining with the other ingredients4 ,melt the tallow and wax over a hot fire until they are thoroughly well mixed4 ,add the dried soap a little at a time1 so that it may become thoroughly incorporated with the wax and tallow4 ,bring the mixture to boiling-point1 then remove it from the fire or stove and ignite the fumes which will then be rising freely4 ,continue the burning process for about fifteen minutes1 then extinguish the flames by replacing the lid of the pan4 ,the shellac and black may be added while the composition is cooling4 ,stone-to-stone re-transfer ink4--,the ingredients of this ink consist of3-- #d oz4 ,transfer ink4 #d oz4 ,litho black ink4 #d oz4 ,medium varnish4 #a oz4 ,canada balsam4 ,melt the transfer ink over a slow fire and add the other ingredients separately4 ,canada balsam will not only add to the effectiveness of this ink1 but it will also improve its working qualities4 ,copperplate transfer ink4--,ingredients consist of3-- #a oz4 ,tallow4 #c oz4 ,bee's wax4 #d oz4 ,shellac4 #b oz4 ,soap4 #d oz4 ,bitumen4 #a oz4 ,canada balsam4 #a oz4 ,carbon black4 ,the method in this case differs somewhat from the preceding4 ,first melt the bitumen and then add the wax and soap in small pieces as before4 ,burn this for fifteen minutes1 and add the shellac1 balsam1 and black1 boiling the whole gently for forty minutes4 ,mould into squares or sticks1 and for convenience in handling cover these with tinfoil4 ,should an extra powerful ink be required for shading or stippling films1 the stone-to-stone re-transfer ink can be reduced to a working consistency with castor oil instead of varnish1 and thus rendered suitable for this purpose4 ,,chapter ,,iii ,,lithographic ,,transfer ,,papers ,essential ,features--,varnish ,transfer ,paper--,damp-stone ,transfer ,paper--,french ,transparent ,transfer ,paper-- ,copperplate ,transfer ,paper--,an ,alternative ,recipe-- ,granulated ,papers--,photo-litho ,transfer ,paper4 ,transfer papers are even more used than the transfer compositions already described1 and in greater variety1 in consequence of which there is a wide difference of opinion concerning their merits4 ,to a certain extent the specific value of any transfer paper must depend upon local conditions4 ,that which might be of the utmost value to one printer would in all probability fail to meet the requirements of another4 ,with these also1 as with the transfer inks1 the main point is to grasp the general principles involved4 ,adhering to these principles enables any intelligent workman to adapt the transfers to his own peculiar necessity4 ,it is most important that lithographic transfer paper should be absolutely impervious to the transfer composition or ink1 so that an impression of full strength can be conveyed to the stone1 leaving its greasy properties unimpaired4 ,the paper therefore must undergo special preparation1 and here again the character of the work and the conditions under which it is carried out are the chief controlling elements4 ,so much is this the case that many lithographic printers prefer to make their own transfer paper1 and find such a procedure eminently satisfactory4 ,a good bank post double foolscap paper1 about #bf lb41 first thinly coated with a solution of concentrated size and afterwards varnished with a heavy coach body varnish1 gives excellent results4 ,when transferring large work in which a number of printings are involved1 and where accuracy of register is a sine qu non1 the following mixture may1 if desired1 be substituted for the coach body varnish3-- ,best oak varnish #a quart4 ,turpentine #a_/b pint4 ,boiled linseed oil #a_/b pint4 ,paper thus prepared rarely stretches or becomes distorted to any appreciable extent1 and can be used with equally good results on either cold or warm stones4 ,its keeping qualities are1 however1 limited2 it is therefore advisable to utilise the transfer impressions with as little delay as possible4 ,this may be criticised as a somewhat primitive and old-fashioned transfer paper2 but of the many transfer papers now in use1 none can claim to be exactly new4 ,another stone-to-stone transfer paper of the simplest possible character can be made by coating a good writing paper with the following composition4 ,soak #c oz4 of glue in #f oz4 of water for about #h hours4 ,reduce #a lb4 of starch to a thick1 creamy paste by rubbing it down in a little cold water and then adding boiling water until the required consistency is obtained4 ,mix the starch and glue together1 and add a little gamboge or cochineal as colouring matter1 so as to enable the printer to see at a glance which is the coated side of the paper4 ,spread this composition on the paper while it is still warm4 ,a transparent transfer paper with a soluble coating is frequently desirable1 and for certain purposes may be strongly recommended4 ,a ,french transfer paper meets such a requirement1 and at the same time possesses many other excellent qualities4 ,it picks up a firm1 clean impression1 and transfers every particle of it to the stone4 ,it is also transparent1 and sufficiently adhesive to stick to a very slightly damped stone under a light pressure4 ,a transfer paper which may be used as a base upon which to write or draw a design for subsequent transference to stone1 as well as for stone-to-stone transferring1 should be coated with a composition of a gelatinous character1 which will not be readily soluble in water4 ,writing transfer ink is of course dissolved in water1 and its effect on a soft1 soluble composition would be disastrous4 ,the following formula is suggestive as well as practical3-- ,gelatine #d oz4 ,isinglass #f oz4 ,flake white #c lb4 ,gamboge #b oz4 ,make a strong size of the above by boiling the gelatine and isinglass with a little water4 ,mix the gamboge and flake white with a little warm water1 and add the mixture to the gelatine solution4 ,this composition must be applied to the paper while still quite warm1 as it forms into a comparatively stiff jelly while cooling4 ,this paper should be transferred to warm stones4 ,copperplate transfer paper is to some extent a development of the variety just described2 that is1 if the conditions under which such transfers are made will bear comparison with operations of an essentially different character4 ,the composition used for coating copperplate transfer paper must possess a somewhat heavy body1 and for this reason plaster of paris enters into its composition1 which is as follows3-- ,plaster of paris #b lb4 ,flake white #a lb4 ,flour #b lb4 ,fish glue #a_/d lb4 ,alum #a oz4 ,soak the alum and glue from #h to #aj hours1 and then boil them until they are dissolved4 ,make the flour into a smooth paste by the addition of a little water1 and mix it with the flake white4 ,mix the plaster of paris with water1 and stir continuously until it becomes incapable of setting4 ,add the other ingredients1 already mixed1 and see that they become thoroughly incorporated with the plaster of paris1 after which coat the paper twice with the mixture4 ,the following may be substituted for the above3-- ,plaster of paris #b lb4 ,flour #b lb4 ,gelatine #d oz4 ,a transfer paper with its surface granulated to represent a mechanical stipple1 or the texture of a grained stone1 may be prepared in the following manner4 ,take of3-- ,starch #i oz4 ,parchment chippings #ab oz4 ,flake white #ad oz4 ,prepare the starch as previously described1 and dissolve the isinglass by boiling4 ,mix the flake white into a thin paste by the addition of water4 ,warm the three ingredients1 and mix the whole thoroughly4 ,coat a fairly heavy printing paper twice with this composition1 and when it is thoroughly dry give it the required granulation by means of grained stones or engraved plates4 ,the grain thus imparted breaks up the drawing into a series of minute dots4 ,paper of this description is most suitable for pencil or crayon work4 ,its usefulness is obvious4 ,it enables the artist to use his chalks in the usual manner1 without the inconvenience of handling large stones4 ,no graining of the stone is necessary1 and the grained effect can be confined to any portion of the design4 ,photo-litho transfer paper is in every respect a specific article1 the coating of which consists of a gelatinous emulsion1 which can be readily sensitised1 and upon which a photographic image can be developed4 ,special preparation and manipulation are therefore necessary in connection with its production1 and these points will be fully dealt with in a subsequent chapter4 ,one more variety of transfer paper should be mentioned1 namely1 the diaphanic1 which possesses excellent qualities for certain classes of work4 ,it is very transparent1 and extremely useful in the tracing of key formes1 or for making facsimile drawings for immediate transference to stone4 ,,chapter ,,iv ,,copperplate ,,transfer ,,printing ,the ,copperplate ,press--,the ,operation--,charging the ,engraved ,plate--,cleaning-off and ,polishing--,making the ,impression-- ,useful ,notions4 ,although copperplate printing may not now be so extensively practised as in years gone by1 it is not1 so far as we can judge1 very likely to be superseded in the near future4 ,it is still regarded as a necessary adjunct to lithography1 especially where the amount of commercial work produced is of any moment4 ,from a purely mechanical point of view the construction of the copperplate press 7,fig4 #c7 is of an exceedingly simple character4 ,its primary purpose is to produce a heavy and uniform pressure on the plate during operation4 ,illustration3 ,,fig4 #c4 ,after being charged with a special pigment and cleaned as hereafter described1 the plate is laid1 face upwards1 on the iron bed or table of the press and in contact with the paper1 and passed through between two iron cylinders4 ,these cylinders are so adjusted as to produce an exceptionally heavy pressure4 ,such are the simple elements of a process which1 however1 requires much closer investigation4 ,in its application to lithography the following are the only requisites for copperplate transfer printing4 ,a stick of prepared transfer ink--whiting1 free from grit--transfer paper1 and a plentiful supply of soft rags4 ,likewise1 an iron plate with a gas jet underneath 7,fig4 #d71 a square of printer's blanket1 and a damp book consisting of twenty or thirty sheets of blotting or other absorbent paper slightly and uniformly damped4 ,illustration3 ,,fig4 #d4 ,a good copperplate transfer paper can be made according to the recipe given in ,chap4 ,,iii41 but unless a fairly large quantity is used the commercial qualities will be found most economical4 ,copperplate printing1 in its application to lithography1 is a simple operation1 but it requires extraordinary care for its successful execution4 ,the conditions under which lithographic transfers are made from a copperplate engraving are vastly different from those which control copperplate printing for ordinary purposes of reproduction4 ,the engraved plate is first well heated by means of the hot plate already mentioned4 ,the transfer ink is then forced into the engraved parts until every line is fully charged1 the ink having been previously enclosed in a double fold of soft rag4 ,during this part of the operation great care must be taken that the transfer ink does not burn through overheating1 as this would partially destroy its greasy nature and leave it hard and brittle4 ,the transfer impression would suffer in consequence1 and1 though to all appearance perfect on the paper1 it would be weak and ineffective when applied to the lithographic stone4 ,such an error of judgment is not at all unusual1 and should therefore be the more carefully guarded against4 ,it frequently occurs without the knowledge of the operator1 owing1 it may be1 to his over-anxiety to complete his work in as short a time as possible4 ,the plate must now be cleaned1 i4e4 the surplus ink and scum must all be removed4 ,this may be done before the plate is quite cool1 and after a little experience it will be possible to accomplish the cleansing process without in any way disturbing the ink in the lines of the engraving4 ,the rag used for cleaning must be tightly folded into the form of a pad and kept free from creases4 ,after final cleansing and polishing with whiting the plate is ready for an impression4 ,the transfer paper requires damping until it is quite limp1 when it is brought into contact with the inked plate and subjected to a very heavy pressure4 ,the backing is a woollen blanket1 preferably of fine texture2 this ensures perfect contact between the plate and the paper4 ,the plate is now very slightly warmed to dry the transfer paper1 which is allowed to peel off2 this it does very readily if1 after a little while1 the corners and edges are but slightly eased4 ,oil of tar will effectually remove any accretions of copperplate transfer ink which may have hardened in the lines of the engraving4 ,it may be useful also to know that it is possible to use a small lithographic press in place of a copperplate press1 assuming1 of course1 that a sufficiently heavy and uniform pressure can be guaranteed4 ,this is not altogether an innovation1 yet it is not a familiar notion4 ,,chapter ,v ,,the ,,lithographic ,,press ,mechanical ,principles--,constructive ,details--,scraper-- ,tympan--,practical ,suggestions--,elastic ,bedding4 ,it is not a little surprising to find that the mechanical principle of the lithographic press in general use to-day is almost identical with that which the pioneers of the craft employed so successfully4 ,this is an interesting fact which either reflects much credit upon the ingenuity of the early lithographic printers or points to an unreasonable conservatism on the part of the present-day craftsmen4 ,a discussion of this phase of the question would be of doubtful interest1 for the practical printer has long been accustomed to regard it simply as a convenient appliance for the production of a heavy and readily adjustable pressure4 ,a brief examination will prove to what extent these requirements are fulfilled by the modern lithographic press 7,fig4 #e74 ,the simplicity of its construction suggests a first point for favourable criticism4 ,in fact1 its general mechanical arrangements are so exceedingly simple that the merest tyro might readily understand their principles and purpose4 ,the adjustability of the pressure by means of the screw ,d 7,fig4 #h7 is both effective and necessary1 owing to the constantly varying thickness of the lithographic stones4 ,the pressure of the boxwood scraper ,b on the surface of the stone is perfectly rigid1 and yet1 owing to the intervention of the tympan ,c1 is sufficiently elastic to ensure the closest possible contact4 ,figs4 #f and #g show one or two constructive details by which the hand lever ,a and the cam motion ,e bring up the cylinder ,f to the bottom of the carriage or bed of the press1 ,fig4 #h4 ,illustration3 ,,fig4 #e4 ,it is in this position that the movement of the carriage gives the necessary pressure required to pull an impression4 ,the shaft ,h runs across the press and operates a similar cam to ,e on the opposite side4 ,these two cams raise the brass block ,g and give the requisite support to the cylinder ,f when the pressure is applied4 ,these are the chief characteristics of the lithographic press1 and as such they require not a little attention and intelligent manipulation4 ,it is practically impossible to secure a steady and uniform pressure unless the scraper and tympan are carefully adjusted4 ,illustration3 ,,figs4 #f and #g4 ,the former must be perfectly true with its ,v-shaped edge nicely rounded1 and the latter tightly stretched on the frame ,c so that it will not sag or bulge when pressure is applied and the scraper passes over it4 ,to reduce the enormous friction caused by this pressure the back of the tympan is usually dressed with a mixture of tallow and plumbago1 a dressing which requires frequent renewal4 ,the plumbago possesses but little body1 and its salutary effect soon passes away4 ,to prevent this and to increase its adhesiveness it is sometimes mixed with a little gum4 ,a mineral black which is found in large quantities in the west of ,england is even more effective than plumbago for this purpose4 ,it forms a strong and flexible dressing for the leather1 is peculiarly adhesive and provides an efficient lubricant4 ,it is a decided advantage to have two tympans in use1 one for small stones and another for the larger sizes4 ,it is obviously unwise to pull a number of impressions from small stones with a large tympan1 for if this practice is persisted in the tympan leather not only loses its shape1 but becomes perceptibly thinner on such parts as may have been most subjected to pressure4 ,for similar reasons it is advisable to have a number of boxwood scrapers of different sizes4 ,the dents produced by a small stone on a large scraper can only be removed by planing4 ,in lithographic press work some form of elastic bedding placed underneath the stone will not only materially assist the pressure1 but will also minimise the risk of breakages4 ,in fact1 the pressure is frequently so keen and of such a direct character as to render this arrangement little short of a necessity4 ,extra thick linoleum will serve this purpose admirably1 and a zinc covering for this bedding will complete the equipment of the lithographic press4 ,illustration3 ,,fig4 #h4 ,the operations directly associated with lithographic press work are of sufficient importance to warrant a full description of each1 and will form the nucleus of the following chapter4 ,,chapter ,,vi ,,lithographic ,,press ,,work ,preparing the ,design--,treatment of an ,ink ,drawing--,chalk ,drawings--,alterations--,value of ,impressions--,offsets--,the ,lithographic ,hand-roller--,proving--,registration--, general ,features--,transferring--,a ,commercial ,necessity-- ,arrangement--,choice of ,paper--,transference to ,stone-- ,preparing the ,forme4 ,the operations directly associated with lithographic press work are more or less of a preparatory character4 ,the preparation of a design1 in its progressive stages1 from the lithographic draughtsman to the printing machine1 is usually carried out in conjunction with the press4 ,only under exceptional conditions or for some particular class of work is the lithographic press actually employed for printing purposes4 ,its ready adaptability to the ever-varying thickness of lithographic stones1 and the manner in which pressure can be applied at will1 as well as the intense sharpness of such pressure1 render it peculiarly suitable for the work now under discussion4 ,such operations will be better understood and probably more easily remembered if they are described in a sequence such as might be presented under average commercial conditions4 ,taking a design as it leaves the lithographic draughtsman1 i4e4 in the form of a greasy drawing on stone1 the first object of the printer is to so prepare it as to preserve the conditions described in ,chap4 ,i4 page #b4 ,this he may accomplish in the following manner4 ,cover the whole stone with fresh strong gum and allow it to dry4 ,then if it be an ink drawing1 wash off the gum with water1 and remove the drawing ink from the surface of the design with a few drops of turpentine and a piece of clean rag4 ,proceed to roll up with a lithographic hand-roller charged with good black printing ink4 ,the consistency of this printing ink can only be determined by the character of the work under treatment4 ,it is therefore a matter of experience rather than rule4 ,heavy designs covering large areas can be worked up with moderately thin ink1 while work of a finer description will most probably require a stronger ink for its successful treatment4 ,between these two extremes there is a variety of conditions and effects which will require a ready recognition and an intelligent adaptation or modification of any operation which may be described4 ,it may even be advisable to rub up the work with a piece of soft rag and printing ink1 but the clearness and crispness of the drawing can best be preserved by a complete removal of the greasy ink with which the drawing was originally made4 ,more particularly is this desirable when heavy1 solid work is in close contact with work of a finer description1 for the excessively greasy character of the artist's drawing ink has a dangerous tendency to smear or spread and to thicken the design1 unless a reasonable amount of care is exercised4 ,after rolling up the work as well as possible1 and having decided that it is firm and strong and is fully charged with ink1 dry the stone perfectly and dust over the design with finely powdered resin or ,french chalk4 ,with a piece of water of ,ayr stone polish away any scum or dirt which may surround the work1 and etch it quickly with a weak solution of nitric acid4 ,cover up with strong gum and dry it4 ,the design is now ready either for proving or transferring4 ,the treatment of chalk drawings1 grained stones1 or transfers from grained paper needs a slight variation of the operations already described4 ,the preliminary etching is generally carried out by the draughtsman by flooding the stone with a mixture of gum and acid1 after which the gum solution is allowed to dry4 ,the chemical change which takes place during this etching is often described as one in which the soap present in lithographic chalks is changed to an insoluble compound4 ,this chemical change is perhaps a somewhat contentious matter1 but the effect and not the principle involved is to us the matter of primary importance1 and this effect is such as to actually prevent any spreading of the design on the stone beyond the lines of the original drawing4 ,returning once more to the operation1 wash off the gum1 and1 having removed the excess of water in the usual way1 roll up firmly with a strong black ink4 ,instead of washing out the drawing with turpentine immediately1 work off the original chalk by rolling up with a good nap roller and taking frequent impressions4 ,in this way the grain of the drawing will be gradually developed and rendered fit for further operations4 ,the stone can then be passed to the prover or transferrer4 ,a ,french writer1 in referring to the importance of really good chalk drawing and printing1 as well as to its artistic and technical value1 once said3 ,the printer requires a fair appreciation of that subtle suggestiveness which gradations of tone can impart to a chalk drawing before he can hope to successfully reproduce the artist's original conception4 ,a good printer handles his roller over a chalk drawing with the same feeling as that with which a violin player handles his bow4 ,by movements rapid or slow1 and by greater or less pressure over certain parts1 he charges the drawing to the proper tone4 ,if at any time the original work requires alterations1 they may be executed in the following manner4 ,roll up the design firmly in strong1 black ink1 and1 after fanning the surface dry1 dust it over with ,french chalk4 ,make the necessary erasures with water of ,ayr stone and etch with fairly strong nitric acid4 ,polish slightly1 and wash well with a plentiful supply of clean water4 ,pour over the stone a very weak solution of alum1 and again wash thoroughly with hot water1 so that its rapid evaporation may leave the work ready for immediate manipulation4 ,alterations may be made by transferring or drawing4 ,in either case it is advisable to gum up the work with strong gum and allow it to stand until dry4 ,the subsequent treatment of any alteration will1 of course1 depend upon their character and extent4 ,as new work1 they should be carefully handled4 ,it is most important that a very weak solution of alum should be used4 ,being an alkali1 a strong solution would have a tendency to dissolve the greasy particles of the drawing and cause them to spread and thicken4 ,it is always advisable to take an impression from each design1 whether it be in ink or crayon1 before it is laid aside for subsequent manipulation4 ,these impressions will not only reveal any inaccuracies or weaknesses which might otherwise pass unnoticed1 but also serve as a useful record and for comparison with other transfers or impressions which may be required4 ,there are other phases of preparatory work which come within the scope of the lithographic pressman1 and as they frequently constitute an intermediary stage between the first drawing of the draughtsman on stone and the making of transfer impressions to facilitate reproduction1 a description at this point will be appropriate4 ,it may be that a key forme only has been prepared1 or perhaps an outline forme with sufficient detail4 ,in either case a number of offsets equivalent to the number of colours necessary for the completion of the design will be required4 ,these are made by taking good1 solid impressions in stiff black ink from the key or outline forme4 ,dust these over with a mixture of three parts ,venetian red and one part lamp-black4 ,lay them in convenient positions on a well-polished dry stone1 and run them through the lithographic press with a light yet firm pressure4 ,the result will be faint yet sufficiently clear offsets of an outline which will enable the lithographic draughtsman to prepare any number of formes1 and these will register or fit each other and the original drawing with perfect accuracy4 ,such outlines will in no way affect the work of the draughtsman1 and will disappear at the first application of the gum sponge or moisture in any form4 ,illustration3 ,,fig4 #i4 ,a lithographic nap-roller 7,fig4 #i7 facilitates the work of the pressman in the preparation and development of original drawings on stone1 and becomes an absolute necessity when crayon drawings on grained stones are operated upon4 ,the preparation and preservation of a roller of this description requires a more than average amount of care and attention4 ,the best rollers are covered with ,french calf-skin with a soft1 velvet-like nap1 and may be prepared as follows4 ,run the roller in crude castor oil for a short time until the leather becomes soft and pliable1 then work out the superfluous oil by repeated rolling in medium varnish1 occasionally scraping off the varnish with a broad blunt knife4 ,continue this for a day or two1 then gradually work into the skin some good non-drying black printing ink4 ,the roller thus prepared may be somewhat harsh1 but a few days' use will bring it into condition4 ,an occasional application of tallow or lard1 say about once a week1 will keep the roller skin soft and pliable1 and counteract the hardening effect of constant contact with the damp surface of the lithographic stone and the oxidisation of the printing ink4 ,proving the work of the lithographic artist1 though not always an absolute necessity1 is a helpful and most important function4 ,in its progressive stage it enables both designer and lithographer to observe the realisation of their colour schemes1 and to amplify or minimise if necessary the effects they desire to produce4 ,errors of judgment or of detail can be rectified before the work reaches a more advanced stage4 ,again1 a finished proof offers something of a tangible character for an expression of approval or disapproval1 and serves as a useful and helpful guide to the printer throughout the subsequent operations4 ,this will show clearly the importance of the prover's work1 and though it is not by any means an unusual proceeding to prove up even the most elaborate designs in the lithographic printing machines1 it is1 for obvious reasons1 more convenient to confine such work to the press4 ,it may therefore be regarded as an intermediate operation1 distinctly apart from the preparation of the original drawing which precedes it1 and the arrangement for machine printing which follows4 ,the distinctive and pre-eminently the most important feature of proving is the manner in which one colour is registered with another2 and although the methods usually adopted are of the simplest possible character1 the most scrupulous care is requisite for their successful application4 ,it appears to be an almost ridiculous plan1 so simple is it1 to cut away the angles formed by the register lines after the first printing 7,fig4 #aj;,a71 and then to place them to corresponding lines on each colour forme1 or to pierce the register lines as in ,fig4 #aj;,b1 passing a fine needle through each puncture into corresponding holes drilled in the stones and allowing the sheets to fall into position1--yet these operations demand constant care and attention4 ,illustration3 ,,fig4 #aj;,a4 ,illustration3 ,,fig4 #aj;,b4 ,the mixing of colours for proving1 and the general principle of their application1 are matters which are almost entirely under the control of the printer4 ,their selection and the manner in which they are employed are both determined by the individual character of the work4 ,it is impossible to indicate any rule of thumb guide for their application or manipulation4 ,the individual fancy of the artist1 or the wish of a customer1 are the only probable complications which may have to be considered4 ,then again1 many phases of the work are more or less experimental1 when the resourcefulness of the printer may be tested1 and the mechanical features of his work be relieved by the exercise of intelligent application1 if not of artistic perception4 ,very rarely is it possible to print from the litho-draughtsman's original drawing1 and even when it may be convenient to do so1 it is1 in the majority of cases1 unadvisable on account of the element of risk involved4 ,there is an ever-present danger of the stone breaking1--a catastrophe which would necessitate an entire reproduction of the design1 and even under the most favourable conditions the constant attrition produced by the rollers1 etc41 would have an appreciable effect on the work1 and in course of time destroy its value for graphic reproduction4 ,many other equally cogent reasons why duplicates of the original should be made for printing purposes present themselves4 ,the chief of these is an essentially commercial one4 ,to reproduce half a million impressions from a single small drawing would obviously depreciate the commercial value of lithographic printing very considerably1 and although there is no record of the circumstances under which the duplicating of original work by means of transfers was first evolved1 it is only reasonable to suppose that it was the direct outcome of a necessity which was as peremptory in its demands as it has been far-reaching in its effects4 ,the method is one by which any number of impressions can be made on a suitably prepared paper1 and with a sufficiently greasy pigment4 ,these can be re-transferred to a lithographic stone1 and in this way facsimiles of the original may be secured and arranged in the manner most convenient for machine printing4 ,great care is necessary in making these transfer impressions4 ,they must be perfectly solid1 yet not overcharged with ink1 i4e4 they must be clean and sharp1 and as nearly an exact replica of the original work as it is possible to make them4 ,that the further description of these operations may be as lucid and practical as possible1 we will apply it to ordinary work-a-day conditions1 and suppose that a design in three workings has been lithographed and prepared for transferring as already described4 ,the size of the work is #g-a_/d in4 by #d-a_/b in41 then the paper on which it is to be printed ought to be double crown1 #bj in4 by #cj in4 ,this will allow #a-a_/b in4 for the gripper and #a_/b in4 margin at the back and sides4 ,sixteen transfers can be pulled from each colour forme on a thin1 transparent transfer paper4 ,mark out a sheet of stout paper as in ,fig4 #aa1 and arrange the transfers in the position indicated by the dotted lines4 ,the gripper margins ,a ,a are determined by the construction of the machines1 and may be varied accordingly4 ,varnished transfer papers may be laid down on a slightly warmed dry stone1 and if ,french transfer paper be used the stone must be slightly damped4 ,if the sheet of transfers is laid down to a board--,fig4 #ab--uniformity of gripper margin will be assured throughout the series1 and the work of the machine printer facilitated4 ,illustration3 ,,fig4 #aa4 ,pull it through the lithographic press with a gradually increasing pressure in the usual way4 ,the varnish transfer paper will be sufficiently tacky to adhere slightly to the surface of the stone1 so that the pressure may be repeated again and again with perfect safety4 ,it may not be possible to remove the base upon which they were arranged1 as it is usual to secure them in position with paste4 ,at this point the manipulation of the two varieties of paper differs slightly4 ,the thin1 transparent variety is usually fastened down to its paper base with syrup1 glucose1 or some sticky composition of a similar character4 ,this paper backing can be removed immediately after sufficient pressure has been applied to fix the transfers to the stone4 ,as this transfer paper is adhesive it is necessary to damp the surface of the litho-stone before it is laid down1 when1 of course1 it will readily adhere1 even under a moderately light pressure4 ,illustration3 ,,fig4 #ab4 ,the further preparation of work1 after being transferred in this manner1 is in many respects similar to the treatment of new work1 but with this important difference4 ,a new transfer should almost invariably be worked up with a soft rag and black ink1 the latter being thinned down with turpentine and varnish4 ,gum up the work1 and allow the gum to dry4 ,roll a piece of soft rag into a pad1 and charge it with printing ink which has been thinned down4 ,wipe off the gum on the surface of the stone1 leaving only a thin film over the work4 ,rub up the transfers with the rag already prepared1 and when fully charged with ink cover them with fresh gum4 ,if possible they should stand for one or two hours1 when the rolling up and etching may be proceeded with4 ,accuracy of register can be ensured by the second and third sets of transfers being patched up to the first forme in the following manner4 ,make two fairly strong black impressions of this forme on a stout unstretchable paper4 ,fix these up on a glass frame in such a position as to allow the light to pass through them1 and carefully place each transfer in its exact position4 ,they can then be laid down on separate stones in the same way as the first set4 ,these are the simple outlines of the transferring process4 ,in detail they may1 of course1 be modified to meet the exigencies of peculiar conditions1 which in lithography are frequently the controlling powers1 and at all times are matters of vital importance4 ,,chapter ,,vii ,,machine ,,printing ,the ,printing ,machine--,the ,halligan--,some ,mechanical ,phases--,speed--,pressure--,levelling the ,stones--,cylinder ,brake--,inking ,rollers--,damping4 ,concerning the structural qualities of the various types of lithographic printing machines now in use1 much might be written and divers opinions expressed4 ,in this respect1 however1 it would be invidious to suggest that one maker's machines were better than another's1 and such would be the natural trend of a discussion on these lines4 ,the machines all have1 it is true1 many points in common where comparisons would be legitimate and easy4 ,yet1 on the other hand1 they each possess distinct advantages which will no doubt appeal to the printer individually1 in proportion to their suitability or otherwise for his particular work4 ,conviction will follow experience in these matters1 and any decision arrived at after this fashion may be regarded as a useful and valuable acquisition4 ,the illustration on page #ce 7,fig4 #ac7 gives a fair general idea of the modern lithographic machine4 ,fig4 #ad illustrates a somewhat novel type of lithographic printing machine1 in which the gripper is entirely dispensed with1 the sheet being held to gauges by the operator until caught between the small cylinder and the stone1 when pressure is immediately applied4 ,the stone is simply blocked up in the bed of the machine and the position of the print on the paper assured by moving the gauges4 ,this useful little jobbing machine is a decided innovation1 and the simplicity of its construction is only equalled by the precision of its movements4 ,illustration3 ,,fig4 #ac4 ,lithographic machine printing presents many peculiar features1 each one of which requires careful and constant attention for their successful operation4 ,some of its purely mechanical aspects--the care of the machine and its accessories1 together with their various functions and applications--offer a wide scope for resourcefulness and ability of a high order4 ,the primary purpose of the machine itself was undoubtedly to accelerate the reproductive power of lithography from a commercial point of view2 and throughout the entire course of its development the aim of the engineer has been to produce a printing machine with an ever-increasing capacity for reproduction4 ,it does not follow1 however1 that the printer's responsibility has been proportionately increased4 ,mechanical appliances have now so far superseded hand labour that1 apart from a thorough knowledge of the principles of lithography1 which is in itself essential1 successful lithographic machine printing is largely due to resourcefulness1 alert perception1 and a skilful blending of mechanical and technical knowledge4 ,illustration3 ,,fig4 #ad4 ,passing over the vast amount of detail which is usually and almost invariably associated with machine printing1 but which offers little that is new to the practical worker1 it might be advantageous to discuss a few points which are too often overlooked4 ,speed1 as has already been pointed out1 is a very important factor in lithographic machine printing4 ,it has become quite a necessity1 and everything which conduces to it should receive the most careful consideration4 ,economy of power is too seldom regarded as a standard of efficiency in the printer4 ,at any rate1 as far as this is concerned it is doubtful if he fully realises the effect of what may appear to him as insignificant matters4 ,a little pressure more or less on the stone may be in itself a mere trifle1 so also would be a careless arrangement of the inking rollers or indiscriminate damping of the stones1 yet1 when taken together1 what a considerable waste of power they might cause2--a waste which is altogether unnecessary and could easily be obviated by care and forethought4 ,excessive pressure is frequently resorted to in order to bring up an impression which is defective owing to some error of judgment in its preparation4 ,it undoubtedly secures the desired effect1 but at what a cost6 ,there is a proportionately heavier drag on the machine and a greater strain on its most vital parts4 ,the following view of this matter may be regarded as somewhat exaggerated1 but it is by no means an uncommon state of affairs1 and will at least serve to emphasise the importance of this point4 ,it is a popular fallacy to suppose that in adjusting the litho-stone to the bed of the printing machine it should be made perfectly level4 ,as a matter of fact a much easier and more satisfactory impression can be made from a stone which is worked just a little higher at the front or gripper edge than at the back1 and for this reason4 ,the drag on the cylinder as it makes the impression is appreciably greater at the back than at the front1 and when the pressure is heavy it has a tendency to leave the back edge with a very decided jerk4 ,the remedy is obvious and simple4 ,as already suggested1 the stone should be set in the machine with the least possible inclination towards the front4 ,this adjustment is easily effected by a judicious arrangement of a few layers of brown paper4 ,just think for a moment of the effect likely to be produced by such a jerk or jar1 which would under ordinary working conditions occur from twelve to fourteen times per minute whilst the machine was in motion6 ,abnormal pressure would of course intensify the strain1 and sooner or later produce results of a decidedly disastrous character4 ,under the most favourable conditions this continual springing would tend to move the stone out of position1 and thus affect the register of one forme with another4 ,another certain result of this condition of things is1 that the sharp pressure on the back edge of the stone would almost certainly cause an appreciable indentation in the cylinder covering4 ,this would eventually cut through1 or at least interfere with the working of a larger sheet at some future time4 ,the mechanism for raising or lowering the lithographic stone in the machine for the adjustment of pressure is comparatively simple 7,fig4 #ae74 ,illustration3 ,,fig4 #ae4 ,there are two screws similar to ,a which pass right through the feet of the stone carriage ,b ,b4 ,a movement of the screws will therefore cause a corresponding movement of the stone carriage on the blocks or inclines ,c ,c4 ,the lock-nut ,d holds the screw securely once the pressure is adjusted4 ,so few printers really understand the proper adjustment of a cylinder brake that some information concerning it will no doubt prove acceptable4 ,in the first place1 a continuous action brake which can be released at certain intervals is most suitable4 ,it holds the cylinders perfectly rigid whilst the machine is running free1 and applies a sufficient check at the points required4 ,the intermittent movement referred to is obviated in various ways4 ,fig4 #ac shows an example of one which is both simple and effective4 ,it might be well also to explain the principle and purpose of the cylinder brake4 ,it is almost impossible to cut mechanical gearing which will run easily and yet be entirely free from slogger4 ,consequently the revolution of a printing machine cylinder would be more or less jerky unless steadied in some way4 ,this is especially the case when it reaches the stone1 and1 owing to the pressure applied1 lifts a little in the gearing4 ,a recognition of this simple matter will enable an intelligent workman to arrange the brake action with judgment and effect4 ,illustration3 ,,fig4 #af;,a4 ,a comparison of the old arrangement of inking rollers 7,fig4 #af;,a7 with the new 7,fig4 #af;,b7 is in itself an object lesson in this question of power and its economical application4 ,it is but reasonable to suppose that the power required to move a set of rollers arranged in the old-fashioned manner 7,fig4 #af;,a7 will be infinitely greater than that which would be needed for such an arrangement as shown in ,fig4 #af;,b4 ,illustration3 ,,fig4 #af;,b4 ,pursuing this matter still further1 the question of indiscriminate damping presents itself4 ,granted that the influence here is an indirect one1 yet it is a cause which frequently leads to an undesirable finish4 ,every printer knows something of the effect produced by excess of water upon printing inks4 ,it hardens and stiffens them by accelerating oxidisation4 ,in course of time their free working on the rollers is interfered with1 and loss of power is by no means the worst result4 ,weak and impoverished impressions1 abnormal wear and tear of the printing forme1 and excessive saturation of the paper may follow4 ,in lithography generally1 and in lithographic machine printing particularly1 the damping of the stone is a matter which requires constant and careful attention2 any arrangements for this purpose should therefore be as effective as possible4 ,the damping rollers should be thoroughly cleaned each day1 in order to remove any scum or grease which may have been collected from the printing forme4 ,illustration3 ,,fig4 #ag4 ,the arrangement of damping rollers shown in ,fig4 #ag is a decidedly practical one4 ,the upper roller consists of metal1 usually brass or zinc4 ,it collects any accumulation of ink or scum from the actual dampers1 and can be cleaned at any time without serious interference with the progress of the work4 ,its adoption1 however1 has not been very general1 although it would be difficult to ascribe any good reasons for such a fact4 ,,chapter ,,viii ,,machine ,,printing--continued ,register--,atmospheric ,conditions--,the ,key--,the ,gripper-- ,starting the ,machine--,fixing the ,stone--,strength of ,colour--,grit--,making ,ready--,regulation of ,speed4 ,it is almost impossible to overestimate the importance of register in lithographic machine printing1 and any suggestions which are likely to be of assistance to the printer in this matter will no doubt be welcomed4 ,variable atmospheric conditions1 insufficiently matured paper1 or constitutional defects in the machine1 are frequent sources of inaccurate register4 ,these may be to some extent unavoidable and therefore beyond the printer's control1 but there are numerous other points which have an important bearing upon the accurate fitting of one colour or forme with another1 and therefore require care and attention4 ,the following method of procedure is well worth consideration1 as it has decided advantages over many others4 ,the key1 or outline forme1 to which the colour formes have been set up1 is put into the machine at the beginning of the printing operations4 ,the exact position of the design on the sheet is arranged1 and twenty or thirty impressions taken on a reliable paper4 ,with these impressions as a guide it is a comparatively easy matter to register each colour accurately4 ,this effects a saving both in time and material1 and rarely fails to produce satisfactory results4 ,during the early stages of the printing1 when it is difficult to detect any slight movement of the stone in the machine1 a sheet bearing an impression of the key may be printed in the usual way1 when any variation in register will be revealed at a glance4 ,the relative positions of the side lay and gripper seldom receive the consideration they ought to have4 ,the gripper and side lay should be exactly at right angles to each other1 and any divergence whatever from this rule simply courts disaster4 ,if they form an acute angle there is a danger of the sheet moving forward a little as the gripper closes4 ,if1 on the other hand1 they are fixed at an obtuse angle1 there is a proportionate risk of the sheet falling back as the gripper closes4 ,if any degree of uniformity could be guaranteed in these movements1 then all would still be well1 but unfortunately no such guarantee can be given1 owing to a possible variation in the cutting of different batches of paper4 ,illustration3 ,,fig4 #ah4 ,another matter of a similar character and quite as important in its issues is more directly connected with the gripper4 ,the type of gripper shown in ,fig4 #ah is probably the best for general use4 ,it enables the printer to use two or more pins upon which to rest his sheet1 according to the particular requirements of his work4 ,two pins are usually sufficient and answer best1 for the following reasons4 ,it is by no means unusual to find that the paper1 trimmed though it may be1 has slightly convex or concave edges1 owing either to insufficient damping or an inaccurate setting of the knife in the guillotine cutting machine4 ,this can1 of course1 be avoided1 but the point at present under consideration is one of possible effects4 ,this contingency and its effect are considerably exaggerated in ,figs4 #ai;,a and #ai;,b1 but for purposes of illustration the suggestiveness of the two sketches is not at all too emphatic4 ,illustration3 ,,fig4 #ai4 ,start the machine with a light pressure1 for once the stone is locked up a certain amount of danger will always exist if at any time it is necessary to reduce the pressure4 ,the stone may still be held by the blocks1 even after the bed of the machine has been lowered1 only to come down with a snap when pressure is applied4 ,such a danger might1 of course1 be averted by slackening the screws and blocks2 but then the stone would almost certainly move out of position and the registration of the forme be altered4 ,narrow slips of paper folded two or three times1 and inserted between the block and the stone1 will often check any tendency the latter may have to lift when the screws are tightened4 ,of the many annoyances associated with the lithographic machine printer's work1 grit is probably the most troublesome1 inasmuch as its presence is almost imperceptible1 while its effect is extensive and often disastrous4 ,its sharp grains become embedded in the inking-roller skins1 and plough tiny furrows across the printing forme1 doing much damage before the printer realises the presence of any foreign matter on the inking-rollers4 ,prevention is a simple matter enough1 but a cure is rarely1 if ever1 accomplished4 ,dust the rollers and examine them carefully before commencing operations1 and in this way ensure perfect cleanliness4 ,it may seem a trifle1 but it is none the less an important one1 and perhaps the reader has already realised that trifles make perfection1 and perfection is no trifle4 ,illustration3 ,,fig4 #bj;,a4--,patent conical counter shafting4 ,illustration3 ,,fig4 #bj;,b4--,patent conical counter shafting4 ,illustration3 ,,fig4 #ba4 ,in making ready on a lithographic printing machine1 as in almost every phase of industrial life1 method is the great secret of success4 ,method conquers the most stubborn difficulties1 and1 though it is not at all times profoundly interesting in its application1 yet it more than repays any monotony it may involve4 ,in the matter of lithographic printing1 at any rate1 a few methods of an essentially simple character might be cultivated with advantage4 ,this chapter is not intended as a complete record of such methods1 but a number of items are discussed herein which1 though simple1 are intensely practical1 and likely to suggest more to the reader than is found described in the text4 ,the question of speed may sometimes seriously handicap progress4 ,it is a self-evident fact that the solid impression of a heavy poster cannot be made at the same speed as a light tint in chromo work4 ,speed cones are usually fixed to a counter-shaft to regulate the speed of the machine as required4 ,figs4 #bj;,a and #bj;,b show an improved arrangement of this character1 in which tapering drums ,a ,a are substituted for cones1 the belt being moved and held in any position by the screw and forks ,b and ,c4 ,d is the driving pulley which transmits the power to the machine4 ,electricity as a motive power for printing machinery is quietly yet irresistibly winning its way into general favour1 and for very cogent reasons4 ,it is the most convenient form of motive power1 and can be transmitted for long distances without any appreciable loss4 ,it takes up little space1 and almost entirely dispenses with belts and shafting4 ,it is also essentially economical1 because it can be applied to the smallest press just as easily as to a #fj' by #dj' poster machine 7,fig4 #ba74 ,,chapter ,,ix ,,lithographic ,,colour ,,printing ,a ,commercial ,value--,peculiar ,features--,colour ,sequence-- ,controlling ,elements--,a ,question of ,register--,suitable ,paper4 ,as a commercial phase of lithographic printing1 colour printing offers a vast and ever-widening field of usefulness4 ,nor is it altogether deficient in these artistic qualities which are pre-eminently suggestive1 as well as attractive and artistic4 ,colour printing1 in its application to lithography1 is in many respects peculiar4 ,it is not what might be described as a self-contained process2 for its successful realisation depends as much upon the harmonious and skilful combination of colours in the design as upon the manipulation of the printing inks1 the sequence of the colour formes1 and their accurate fit or register during the actual printing4 ,the most excellent printing would produce barely passable results unless the design was effectively arranged1 and prepared with some consideration for the conditions under which it might be printed4 ,nor is it at all unlikely that a design1 however smart and artistic it might appear in its original form1 would be irretrievably spoiled by clumsy handling or careless printing4 ,the subject for immediate consideration is the practical employment of printing inks for the reproduction of coloured designs1 their qualities1 peculiarities1 and relative values1 as well as the means employed to make them amenable to commercial conditions4 ,an intelligent appreciation of these points will not only extend the possibilities of printing inks1 but will also enable the machineman to accentuate their attractive and suggestive power4 ,colour is to design what salt is to food1 and successful colour printing has been very aptly described as the adaptation of printing ink to the ever-varying character of work and conditions of employment4 ,this very practical definition will form the keynote of a chapter which1 by the very nature of things1 must be to some extent authoritative and comprehensive4 ,the colour sequence1 i4e4 the order in which the colours must be employed to secure the best and most economical results1 is of primary importance in colour printing4 ,on broad lines1 the principle usually followed is one in which the opaque colours are printed first1 and upon these all secondary effects are built up4 ,this building up of colours plays also a most important part4 ,its relation to colour sequence is a necessary and influential one4 ,for example1 it might not be absolutely essential that even a yellow should be printed first1 if it did not form the base for the building up of a green by the super-position of blues1 of an orange effect in conjunction with red1 or as a secondary flesh tone under the buff4 ,the difference between printing a blue over a red or vice vers is also very striking4 ,one produces a purplish-black brown1 and the other a rich chocolate-brown4 ,other complications of a similar character are common1 but these will indicate with sufficient clearness the possible modifications of colour sequence4 ,another feature upon which colour sequence in printing largely depends is the point at which the outline forme can be most effectively introduced4 ,it is advisable to print the outline forme at as early a stage as possible for obvious reasons4 ,perfect registration is far from easy to secure4 ,red in the lips1 blues in the eyes1 and isolated touches of colour in various parts of the design must fit the browns1 and therefore fit each other1 and yet they may have no direct relation to each other in the printing4 ,a remedy has been already suggested1 but once an outline forme is printed the cause of bad registration is to some extent removed1 and a remedy quite unnecessary4 ,when worked on reasonable lines it is frequently an advantage to make the outline one of the earlier printings1 so that any harshness of contour1 etc41 may be toned down by the succeeding greys4 ,it is often a matter of personal opinion1 or perhaps of circumstance1 which decides the final printings4 ,the pink may be reserved to impart brilliancy and warmth to the prints1 or it may be equally suitable to hold back a grey1 and1 by regulating its tone and strength1 soften down any tendency to hardness1 pick out the darker prints1 and emphasise the shadows4 ,even these suggestions1 although usually regarded as standard ideas1 must be subjected to modifications under certain conditions4 ,here is a practical instance4 ,unless paper is unusually well seasoned and of first-rate quality1 the temperature of the workroom equable1 and the printing machine in good order--a combination of excellences which is unfortunately rarely met with--the colour sequence must be of a fairly elastic nature4 ,to print a gold first is quite usual1 because the bronze powder will persistently adhere to any preceding printings4 ,from that standpoint alone such a procedure would be eminently practical and convenient1 but suppose for a moment that the gold must fit a later printing with absolute accuracy1 e4g4 an outline forme1 or as forming the base for some ornamental scheme1 then the difficulties which arise are somewhat trying1 and for this reason4 ,the paper being new1 the most serious distortion of any kind is likely to occur during the first printings1 and so long as yellows1 fleshes1 or other colours of a similar character are printed first1 no serious difficulty is likely to arise2 but with the gold printing it may be altogether different4 ,it is quite possible to make both yellow and flesh dry dead1 i4e4 without even sufficient tack to catch the almost impalpable bronze powder4 ,at the same time1 care must be exercised that the colouring matter is not left dry on the surface of the paper owing to its separation from the reducing medium4 ,this plan has been adopted under actual commercial conditions and with conspicuous success1 and it is therefore offered as a preventive measure which is free from many drawbacks which are the frequent accompaniment of novel ideas and operations4 ,here then is a simple practical summary of the idea4 ,the yellow and flesh1 or equivalent colours1 are printed first1 so that they will dry free from gloss or tack4 ,the fit required between such colours and subsequent printings is generally a matter of minor importance1 and at this stage distortion of the paper1 whether it be by stretching or contracting1 will not seriously depreciate the value of the print when completed4 ,register between the gold and an outline is frequently of an entirely different character1 and in many cases the slightest variation will be readily discernible1 and have a decidedly bad effect on the finished work4 ,apart from this1 the questions which decide or control the colour sequence have been clearly indicated previously4 ,this matter may be one of convenience also1 for unless otherwise predetermined it would be unwise and far from economical to print a blue before a yellow1 or a black before a red1 etc4 ,the amount of cleaning up thereby involved would become a serious and distinctly disagreeable item1 and purity of tone in the lighter colours would be conspicuous by its absence4 ,the matter of well seasoned printing paper has been already referred to4 ,for effective colour printing the paper must also possess several other essential qualities4 ,it should be firm in substance1 sufficiently absorbent to carry the successive layers of printing ink1 as far as possible unstretchable1 and should present a smooth surface though not a glazed one4 ,the chalky1 dull1 enamelled papers offer many recognised features of value to the colour printer4 ,they assist in the absorption of the ink as well as afford a suitable surface for their impression4 ,friction-glazed and other prepared papers are also excellent for colour printing by lithographic methods4 ,,chapter ,x ,,lithographic ,,colour ,,printing--continued ,printing ,inks--,varnish--,reducing ,medium--,relative ,values-- ,some useful ,hints--,bronze ,blue--,vermilion--,ink ,mixing-- ,ceramic ,transfers--,colour ,transparencies4 ,for the successful manipulation of printing inks of any description it will be necessary to know something of their composition1 or at any rate of such features as render them peculiarly suitable for printing purposes4 ,from a printer's point of view the most important of these features is what may be described as the reducing medium1 i4e4 the medium which holds together the various colours so as to produce pigments of suitable working consistency4 ,the most useful and the commonest form of reducing medium is a linseed oil product1 known in its prepared state as a lithographic varnish1 with a supplementary title indicating its specific character4 ,its value to the lithographic printer lies mainly in the fact that when it is fully matured it possesses a good full body along with fair drying properties and freedom from any excess of greasy matter4 ,this varnish is used in three or four consistencies between which any degree of strength may be arranged by mixing4 ,a brief outline of the manner in which they are prepared may still further emphasise their usefulness in lithographic printing4 ,raw linseed oil is matured and oxidised until its consistency is considerably reduced4 ,it is still further reduced by being boiled at a high temperature1 and is known commercially as boiled linseed oil4 ,as this boiling is continued the fumes which quickly rise can be ignited1 and the liquid soon assumes a syrupy or stringy character1 according to the length of time during which it is subjected to the action of fire4 ,by extending or discontinuing the burning the varnish is produced in three grades--thin1 medium1 or strong4 ,lithographic varnish is a good servant but a bad master1 and it is a generally recognised fact that1 beyond a certain point1 lithographic varnishes as a reducing medium will depreciate the value of colour4 ,the chief requisite in colour printing is the production of a solid flat impression1 and for this purpose almost all printing inks must be reduced to a suitable working consistency4 ,to accomplish this1 and at the same time retain the full colour strength of printing ink1 a soft1 free-working composition will be useful and desirable4 ,there are several commercial varieties of solid oil from which the excess of grease has been extracted4 ,these form excellent reducing mediums4 ,they break down the tack of stiff pigments and enable them to work freely during the printing operations4 ,the drying of inks thus prepared is not seriously retarded2 they lift readily and usually produce brilliant impressions4 ,there is a reasonable and logical explanation of these peculiarities which is both interesting and suggestive4 ,whatever the character of a reducing medium may be1 its effect on the strength of colour will of course be in proportion to the quantity used4 ,in all probability #a oz4 of a solid oil composition1 otherwise known as lithographic reducing medium1 would soften down a quantity of printing ink for which at least three times its bulk of varnish would be required4 ,consequently1 the depth of colour and covering power of an ink reduced with litho medium would be proportionately greater than that reduced with varnish4 ,vaseline in some of its commercial forms is frequently used by ,american printers1 and even in this country its use is being tardily1 though none the less surely1 recognised4 ,a few remarks anent the intelligent application of a softening medium may not be inopportune4 ,considerable care and judgment must always be exercised or there will be a loss of cohesion in the colour pigments which cannot fail to prove disastrous4 ,the tendency of lithographic varnish is to bind the colour pigments together1 and this should not be entirely counteracted by the addition of fatty compositions1 lest the printing inks run scummy during printing operations1 and in drying leave the colouring matter1 from which they have been detached1 on the surface of the paper in the form of a dry powder4 ,such lack of cohesion may1 however1 be an inherent feature of the ink itself1 and not be produced in the manner just indicated4 ,bronze blue affords a striking example of a printing ink of this character4 ,it is1 in fact1 a constitutional weakness which cannot apparently be prevented1 but which is fortunately not incurable4 ,the addition of a little ,canada balsam to bronze-blue ink will add considerably to its working qualities4 ,the loose particles of the pigment appear to be held together without becoming harsh or stringy1 as might easily happen if varnish of sufficient strength was added to produce the same effect4 ,other colours1 again1 such as vermilion and yellow1 owing to their weight and texture1 will always require a fair percentage of varnish in their composition4 ,at the same time1 a little reducing medium might also prove beneficial4 ,referring once more to the fact that vermilion1 as distinguished from its imitation1 is unusually heavy1 etc41 it may be useful to know that for blocking out work it has no equal in all the range of printing inks4 ,it possesses unrivalled opacity1 and as a blocking-out agent frequently plays an important part in colour printing4 ,of the other printing inks1 few possess characteristics of a sufficiently striking character to require special mention4 ,their working qualities present no exceptional difficulties1 and their employment either under primary or secondary conditions is almost invariably determined either by the character of the work or some such conditions as have been already indicated4 ,when the strength of a colour is problematical1 or its effect more or less a question of experiment1 it is a safe plan to mix it a little lighter than will be required4 ,for obvious reasons it is much easier to alter the line or tone of a light colour than that of a darker one4 ,the arrangements for extensive and economical ink mixing need not be of a very elaborate character4 ,standard colours might with advantage be mixed in large quantities and kept as stock shades4 ,fleshes1 pink1 blues1 greys1 etc41 are all useful colours which are in constant use4 ,a warm or cold tone could be imparted to a stock grey as required1 and a similar method adopted with regard to the other colours4 ,other peculiar conditions could be met in a similar manner1 and many economies thereby effected4 ,although the foregoing remarks refer mainly to lithographic colour printing generally1 they may with equal effect be applied to many of its more specific branches4 ,colour printing for tin-plate decoration will be fully discussed in a subsequent chapter4 ,transfer printing for ceramic decoration presents many features in common with transfer printing for metal decoration4 ,printing colour transparencies is a commercial phase of colour work which is productive of many curious and attractive effects4 ,unlike the ordinary colour prints1 the transparency is intended for exhibition both by reflected and transmitted light4 ,the paper is of a thin1 tough quality1 and the first printing is usually a white of good covering power and exceptional opacity4 ,it is not necessary to print a solid white groundwork for the coloured design4 ,if an intense brilliant colour is required by transmitted light the omission of part of the white printing will add considerably to the effective character of the design4 ,a brilliancy secured in such a manner may be still further intensified by printing the colour or colours in register on both sides of the paper4 ,this can be easily accomplished by first allowing the cylinder covering to take an impression from the stone1 and then1 with the sheet laid in the gripper1 make a second impression in the usual way immediately after4 ,the first print1 which might be termed the transfer1 will then be made in accurate register on the back of the sheet4 ,semi-transparent1 or even transparent1 effects can be obtained with any of the colours by an omission of the white printing from the parts affected4 ,complete opacity may be secured by its introduction4 ,this print is afterwards rendered more or less transparent by coating it with a suitable varnish4 ,,chapter ,,xi ,,substitutes ,,for ,,lithographic ,,stones ,metal ,plates--,preparation--,manipulation--,d escriptive ,details--,machine ,printing--,the ,printing ,bed--,rotary ,printing ,machine4 ,metal plate1 as a substitute for stone1 is now such an important factor in lithography that the printer who wishes to consider himself thoroughly efficient must possess a fairly comprehensive and practical knowledge of its manipulation and possibilities4 ,the prejudice which has hitherto checked the progress of this branch of lithography was not altogether of an unreasonable character4 ,the plates themselves were far from reliable1 and the difficulties resulting therefrom were a fruitful source of trouble and expense4 ,metal1 as a printing surface1 is even yet a comparatively new factor in lithography1 and the majority of printers have been working with lithographic stones from their apprenticeship till the present time4 ,it is not surprising1 therefore1 that in relation to the use of stones almost every possible contingency has been provided for1 but with metal plates a little fresh knowledge must necessarily be acquired before the workman can claim the same familiarity of manipulation which he may feel towards the parent process4 ,this is1 in fact1 the point upon which the whole question usually turns4 ,good work can be produced from zinc and aluminium plates1--of that there is not the slightest doubt1--and it is equally certain that the advantages offered by their use are of a substantially practical character4 ,they can be handled with ease and with absolutely no fear of breaking4 ,they are much less costly than stone1 and require less storage room4 ,a grain of a finer and sharper texture can be imparted to metal than is the case with stone1 and what is even of greater importance1 the character of such a grain remains unaffected for a considerable time4 ,surface inequalities are rarely met with in metal printing surfaces1 and consequently uniform pressure is to a certain extent guaranteed4 ,in photo-lithography it is possible to make a print from a negative direct on to the plate 7,chap4 ,,xvii4 page #ajj74 ,this ensures an original of exceptional clearness and strength1 especially in half-tone subjects4 ,although an ordinary zinc plate1 which has been carefully polished to free it from every trace of grease1 can be used for lithographic printing1 the best results are obtained from plates which have been specially prepared4 ,a slight de-polishing with pumice sand and a piece of felt may impart the requisite tooth to the face of the plate1 or the following method may be adopted3--,clean the plate with pumice sand and felt1 and immediately immerse it in a hot bath containing3-- #ah oz4 ,water4 #a_/d oz4 ,alum4 #a dram ,nitric acid4 ,keep this liquid in constant motion over the face of the plate until it assumes an even1 silvery-grey appearance1 and then wash it thoroughly with a plentiful supply of clean water4 ,dry at once1 and quickly4 ,these plates can also be sand-grained by specially constructed machinery1 or a variety of grains and stipple can be imparted to their surface by etching or sand blast4 ,a novel yet practical idea1 which has met with considerable success1 is to electrolytically prepare the surface of the plates4 ,the value of this preparation has been amply demonstrated by its extensive adoption and successful use4 ,another distinctly progressive feature is a deposit of alumina on the zinc1 which for printing purposes gives it all the advantages of an aluminium plate4 ,illustration3 ,plate-graining machine1 showing oscillating motion4 ,transfers can be made on metal plates in much the same manner as on lithographic stones4 ,for press work mount the plate on a piece of cardboard its own size1 then1 having gummed a sheet of brown paper on the face of the litho-stone1 place the mounted plate near the centre and fasten it with paste or gum4 ,this will prevent it moving about1 and also raise it sufficiently from the stone to enable the printer to use his damping-cloth and roller freely4 ,before mounting1 the back of the plate should be carefully dusted to free it from grit and dirt4 ,after the drawing or transfer has been made cover the surface of the plate with strong gum1 and while this is still wet add to it a solution of bichromate of potash4 ,leave a slight film only of the gum bichromate1 and then dry it quickly and thoroughly4 ,wash out the work with turpentine1 not with water4 ,the gum1 being insoluble in turpentine1 remains unaffected4 ,illustration3 ,plate-graining machine1 showing interior of trough4 ,roll the plate up solid in black ink1 sponge it over with water1 damp it with a cloth1 and then roll it up in the usual way4 ,when the work becomes fully charged with ink1 dust it over with a mixture of resin and ,french chalk1 and etch it with the acid etching solution4 ,every maker of zinc and aluminium plates supplies this special etching solution1 prepared for a certain quality and character of metal4 ,it is advisable1 therefore1 to use the preparation recommended1 and thus avoid the many pitfalls which beset the path of the experimentalist4 ,the plate is now well washed over with clean water1 and thinly gummed up4 ,when the gum is dry wash out the work on the top of the gum with dry flannel or felt till all the work is removed1 sprinkle a few drops of water on the plate1 and with a rubbing-up rag and a little ink and turps rub up the work till it is gently charged with ink1 then roll up till work or transfer looks strong and sharp1 when the plate is ready for printing4 ,for etching and rolling up chalk drawings on grained plates3 ,pour in a saucer some of the etching solution1 and add about the same quantity of fresh1 strong gum4 ,this solution is evenly distributed all over the plate with a camel-hair brush1 and left to dry4 ,then the etching is removed with water1 and the plate very thinly gummed up and left to dry4 ,now the work is washed out with turps and a piece of dry1 soft felt or flannel1 without water1 till all the work disappears1 and the plate rolled up solid black4 ,then sponge over with water-sponge1 damp over and roll up till work appears nice and sharp4 ,now dust over with resin and ,french chalk1 and etch again with the etching solution1 full strength4 ,after the etching has dried remove the same with water1 and gum up again4 ,when drawings are to be washed out for proofing or printing1 the plate should first be thinly gummed up4 ,this gum layer is left to dry thoroughly1 and is not removed when the work is washed out 7without water7 with turps and a dry piece of flannel or felt4 ,next wipe away all the black ink and turps1 still using no water for this operation4 ,should any black work be left1 use some more turps on the clean dry rag till all the work has been removed1 then sprinkle a few drops of water on the plate1 and use a clean rag to remove the gum layer and loose black ink left on the plate1 then damp over as usual and roll up4 ,plates treated in this way retain the grease contained in the drawing1 and the work rolls up easier and quicker1 and none of the finer work gets weakened or lost2 also1 the plate keeps cleaner and free from scum4 ,when alterations are necessary the work should be rolled up with a strong black ink1 and dusted over with ,french chalk 7powdered talc74 ,remove the part which requires altering with a mixture of equal parts etching solution and turpentine on a small piece of felt or flannel1 and rinse well with water4 ,pour some special re-preparing solution in a saucer1 and apply this solution with a camel-hair brush to the parts where the work has been removed2 after the solution has remained for a few seconds rinse well with water4 ,this operation is to be repeated several times till the surface looks clean1 no work being visible2 and after the plate is dried with clean white blotting paper it is ready to receive the additional work4 ,when the alteration has been made1 the rolling up should be done with the bichromate solution1 as per general directions4 ,illustration3 ,,fig4 #bb4 ,illustration3 ,,fig4 #bc4 ,where the alterations involve additional work only without erasures roll up the design first with a good1 strong ink1 and dust over with ,french chalk4 ,the special re-preparing solution is used in the same manner as acetic or citric acid is employed on a litho-stone4 ,for this purpose we recommend that the special solution should be diluted with an equal quantity of clean water1 and the solution applied with a camel-hair brush4 ,it should remain on for a few seconds1 and then be quickly rinsed with clean water4 ,this operation may with advantage be repeated two or three times for securing a clean surface for the additional work4 ,when the plate has been thoroughly dried with clean blotting paper it is ready to receive the additional work4 ,the rolling up should be done with the bichromate solution1 as per general directions4 ,machine printing from zinc or aluminium plates requires but a slight modification of well-known methods2 and although it may in some respects present entirely new features1 the making ready of work in which several printings are employed is simplified1 and consequently much time is saved4 ,in the ordinary type of litho-printing machine the printing bed 7,fig4 #bb7 is levelled in the machine for the first printing1 and1 if this is carefully arranged1 no alteration will be required throughout the whole series2 for1 in changing from one colour to another1 the printing plate can be slipped from the bed and another substituted in a very few minutes4 ,the most scrupulous care should be exercised at all times to prevent dirt or grit of any kind insinuating itself between the surface of the printing bed and the back of the plate4 ,it is not in connection with the flat-bed printing machine1 however1 that the most decided progress is likely to be made in surface printing from metal plates4 ,the change which is already foreshadowed in the printing mechanism of to-day is shown by the growing demand for the rotary in place of the slow and tedious movements of the flat-bed press4 ,the mechanical principle of the rotary machine 7,fig4 #bc7 at once suggests an absolute precision of movement which it is scarcely possible to guarantee in the flat-bed press4 ,there is no appreciable lift in the gearing of the cylinders when the impression is made1 and practically no risk whatever of slogger1 such as that described in ,chap4 ,,vii4 page #ch4 ,the uniform velocity of the cylinders1 which is to a great extent due to the points already indicated1 considerably reduces friction1 produces perfect registration1 and enables the machine to be worked at a high rate of speed4 ,the machine shown on page #fc presents many novel and essentially practical features4 ,the side elevation 7,fig4 #bd7 gives a fairly accurate idea of its general mechanical principles4 ,illustration3 ,,fig4 #bd4 ,,chapter ,,xii ,,tin-,,plate ,,printing ,its ,evolution--,transfer and ,direct ,transfer ,printing--,the ,coated ,paper--,reversed ,designs--,sequence of ,printing-- ,printing ,inks--,purity of ,tone--,drying4 ,tin-plate printing or decoration is probably the most remarkable development of modern lithography4 ,from a most unpretentious and unpromising beginning its evolution has been an unbroken record of phenomenal progress4 ,owing to its intrinsic merits and peculiarly assertive character it has created an enormous demand for its own productions4 ,difficulties innumerable were encountered and surmounted1 whilst a whole host of trade prejudices had to be removed before anything approaching a commercial success could be claimed4 ,the original idea was to transfer a printed design from a suitably prepared paper to the metal plates in much the same manner as the children of to-day use transfer prints for decorative and other purposes4 ,though this method is now to some extent superseded1 it is by no means obsolete4 ,it is extensively used for certain classes of work1 and so long as the present type of direct tin-printing machine is used this transfer method of metal decoration will more or less be retained4 ,it is difficult1 and in some cases impossible1 to print unusually large or exceptionally thick metal plates by the direct process4 ,hence the value of ,transfer ,printing as a useful auxiliary process which can be resorted to without the expense of special machinery4 ,the ordinary lithographic paper-printing machine1 without any modification whatever1 will fulfil every requirement4 ,almost any paper which has been coated with a starchy composition will be suitable for ,transfer ,printing4 ,though not absolutely essential1 it is decidedly an advantage to use a paper which is somewhat porous1 not too hard4 ,a brief description of the principles involved will probably lead to a clearer understanding of the points already indicated4 ,the print is made on the starchy composition with which the paper is coated1 and never actually penetrates to the paper itself4 ,this composition1 being readily soluble in water1 can be transferred from its paper base to any other surface1 and will carry with it any print or impression previously made thereupon4 ,in theory1 then1 this process is exceedingly simple1 nor is it likely to present any insuperable difficulties in practice4 ,one of the most important features of ,transfer ,printing1 which affects not only the colour sequence but the draughtsmanship1 is the inversion of the design when printed4 ,to the printer who is accustomed to chromo work on paper1 this matter will probably offer many awkward situations4 ,the control over colour effects is somewhat restricted1 and consequently not only care and skill1 but a certain amount of special training and actual experience1 will be necessary for the production of really successful work4 ,in theory the outline forme should be printed first1 but in practice it is frequently advantageous to introduce some of the transparent tints as first printings4 ,in the first place1 such prints rarely affect the design to any great extent as far as register or fit is concerned4 ,consequently1 any distortion of the paper from atmospheric or other causes has no very serious consequences1 and such distortion1 i4e4 expansion or contraction1 would be most likely to occur during the initial printings4 ,there is yet another and equally important reason for this suggested modification of the colour sequence4 ,the light1 tacky tints considerably improve the printing surface offered by the mucilaginous coating of the paper1 and the stronger inks can be printed on it with a full body of colour yet without any tendency to smash and smear4 ,the lighter tints1 then1 are printed first1 and these are followed by the opaque colours1 reds and yellows being last4 ,the peculiar feature of such an arrangement is that1 after the first few printings1 the design becomes partly obscured1 and the relative value of different colours1 together with the effect of their super-position1 are frequently questions of skilful calculation rather than visual appreciation4 ,thus successful manipulation is therefore more or less the result of careful observation and wide experience4 ,in certain classes of work it may1 of course1 be absolutely essential to ascertain the effects of colours as they are printed4 ,this can be done by transferring a progressive print to a sheet of dull enamel surface paper1 using gum water as a transferring medium4 ,in all work where specific colour effects are required it will be advisable to make such test transfers again and again at different stages of the work4 ,concerning the printing inks themselves but little need be said4 ,they must be of good quality1 varnishable1 and of intense colouring power4 ,purity of tone is requisite1 not only under ordinary circumstances1 but under what may be regarded as exceptional conditions4 ,the print1 when subsequently transferred to the metal plate1 will be placed in a stove having a temperature of #adj ,fahr4 ,few colours remain quite unaffected by this stoving1 but with carefully selected printing inks the effect is scarcely perceptible4 ,it can1 moreover1 usually be anticipated1 and to some extent minimised1 either by judicious super-position or skilful preparation of the colours themselves before printing4 ,the following example will suggest a number of expedients for the preservation of tone of colour in tin-plate decoration4 ,pale blues will frequently become of a decidedly greenish hue when varnished or stoved1 and this may be modified by an exaggerated intensity of colour1 even to hardness1 when printing4 ,at the same time1 it must be remembered that blues are seldom1 if ever1 affected in tone4 ,pinks of the lighter shades1 on the other hand1 may suffer both in hue and tone4 ,reds may be mixed with a more liberal amount of lake than they apparently need1 and then backed up with solid masses of yellow and flesh4 ,these will restore the bright vermilion hue1 and likewise give a greater amount of density or covering power to the colour4 ,black1 in the same manner1 may be intensified by an underlay of blue4 ,as far as purity and density are concerned1 the white printing is by far the most important4 ,the primary function of this printing in tin-plate decoration is the formation of an opaque ground on the metal plate--equivalent to the white paper4 ,without it the colours of a design would lose their brilliancy and effect1 for their purity and density would be affected by the lustrous sheen of the bright metal plate4 ,it is a printing1 then1 of some1 importance1 and the most scrupulous care should be exercised during its manipulation4 ,in consequence of the exceptional density required it is usual to repeat the white printing either two or three times4 ,the first printing especially should be made with a smooth1 well-mixed ink1 which should be worked with the intention of securing a perfectly flat and solid impression rather than a heavy body of colour4 ,the requisite amount of density can be obtained by the second or third impressions4 ,a slight tinge of ,oriental blue given to the white will improve its appearance and counteract the discoloration produced by the varnishing and stoving4 ,another point with which the average printer is not familiar is the unusually rapid drying of each colour4 ,the printing inks must dry on the surface1 and not even in the slightest degree be allowed to permeate the paper4 ,this is1 in fact1 the crux of the whole matter2 and1 assuming that the coating of the paper is suitable and perfect1 the drying cannot be otherwise than on the surface4 ,dryers1 preferably liquid1 must be mixed with the printing inks in liberal quantities4 ,here1 again1 experience alone can be relied upon for guidance4 ,printing inks have their peculiar characteristics1 and atmospheric conditions are ever varying4 ,it would therefore be unwise to indicate any hard-and-fast lines upon which to work4 ,there is at least one danger accompanying the use of dryers in any form which must not be overlooked4 ,colours may dry too hard and present for the succeeding printings a surface similar to a varnished sheet1 which will offer no grip to the printing ink1 and upon which it will probably run1 and1 consequently1 produce a defective impression4 ,this is by no means an infrequent occurrence4 ,experience alone can prevent it1 but the remedy is as simple as it is effective4 ,briskly rub each printed sheet with a pad of soft rag and a little magnesia or ,french chalk4 ,magnesia is best4 ,it is an almost impalpable powder1 and has no ill effect even upon the most delicate tints4 ,this rubbing will produce a slightly matt surface on the hard glossy ink1 and on this a good solid impression may be made without further trouble4 ,the printed sheets should be exposed to the air for a few hours to accelerate drying4 ,this may be done in any convenient manner1 either by laying them out in frames or hanging them up4 ,a set off in ,transfer ,printing should be sedulously avoided2 not that the soiling of the back of a sheet is of any moment1 but because the matter set off on the back of one sheet must be pulled off the face of another1 and that very often in liberal proportions4 ,,chapter ,,xiii ,,tin-,,plate ,,printing--continued ,direct ,tin ,printing--,the ,machine--,peculiarities of ,impression--,cylinder ,covering--,colour ,sequence--,printing ,inks--,drying ,racks--,air ,drying and ,stoving4 ,direct tin printing is not1 as the term might suggest1 a direct impression of the printing forme on the metal plate4 ,it is in reality a transfer printing process in which the transferring medium is a cylinder with an elastic covering4 ,this additional cylinder is one of the chief characteristics of a direct tin-printing machine1 and1 apart from a few accessory movements1 it is in this respect alone that it differs from an ordinary lithographic printing machine4 ,fig4 #be gives a sufficiently clear idea of this distinguishing feature4 ,a detailed description of its mechanical principles is unnecessary1 but the following points will prove helpful4 ,the impression is made from the printing forme upon the lower cylinder during the first half of its revolution1 and transferred to the metal plate1 which is carried by the upper cylinder as the revolution is completed4 ,the reciprocal movement of these two cylinders is therefore a matter which demands the keenest possible attention4 ,their pitch must be absolutely accurate1 the pressure of one against the other nicely adjusted1 and the brake arrangement on both such as to ensure a perfectly steady revolution4 ,the lower cylinder is covered with a three-ply rubber blanket1 which provides a sufficiently elastic impression surface4 ,illustration3 ,,fig4 #be4--,rapid tin-plate printing press4 ,this rubber covering is a most important feature1 and requires both careful adjustment and intelligent use4 ,careful adjustment is requisite to ensure the tension being perfectly uniform over the whole surface1 when the material is drawn taut by means of a tooth-and-ratchet arrangement4 ,were it not so1 the printing surface presented would naturally vary in thickness and resilience1 in consequence of which the pressure would be variable and the impression distorted4 ,a most remarkable peculiarity of this rubber covering is that it has a very decided influence upon the size of the impression4 ,if1 for example1 its pressure upon the printing forme is increased1 the impression will be slightly less than the work on the stone1 whilst a lighter pressure will of course produce the opposite effect4 ,it is advisable1 therefore1 when making a first impression1 to measure it from back to front and compare it with the printing forme4 ,this method will ensure a print of the exact size1 and avoid any risk of complications in the subsequent printings4 ,such distortion--for a distortion it really is--may frequently be turned to good account1 and under certain conditions it may prove to be a help rather than a hindrance4 ,some slight inaccuracy in the fitting of any part of the design may occasionally be corrected by inserting patches of thin paper under the cylinder covering1 so as to almost imperceptibly increase the pressure over the required area4 ,this idea in its application to making ready at a tin-printing machine will suggest many possibilities to the resourceful printer1 and if intelligently treated will rarely prove troublesome4 ,in a lesser degree the same system of packing may be applied to the upper cylinder1 and the size of the impression to some extent controlled during its transference to the metal plate4 ,the speed of the machine also affects the impression1 and in a somewhat peculiar manner4 ,several theories have been set forth to prove why an increase in speed should produce a slight enlargement of the impression1 and vice vers2 but it is doubtful if any of them are altogether satisfactory4 ,most probably it is due to a momentary change in the resilience of the rubber4 ,the character of the pressure1 which is certainly influenced by increasing or diminishing the speed1 would of course effect such a change4 ,the effect1 as just indicated1 is1 however1 only perceptible when a very pronounced variation in the speed takes place4 ,a rubber blanket is also affected in a somewhat similar manner by atmospheric changes1 though not appreciably by moisture4 ,one other point in connection with the cylinder covering is worth noting4 ,whenever it is necessary to remove the impression from the blanket1--and the necessity may arise many times during the course of a day's run1--let it be done with turpentine or benzole1 and as rapidly as possible4 ,after the superfluous turpentine or other cleanser has been wiped off1 dust over the blanket with ,french chalk4 ,this will completely absorb any of the cleanser which may have permeated the rubber1 and thus minimise any injurious effect4 ,unlike the ,transfer ,process in ,direct ,printing1 the colour sequence is practically the same as for paper printing4 ,there are1 of course1 essential points of difference1 and these may fitly mark the next stage of progress in the discussion of this subject4 ,in the first place1 a bright metal plate does not present an altogether suitable printing surface1 and for several reasons4 ,the sheen of such a plate will show through many of the printed colours with a dull metallic lustre4 ,the surface1 again1 is hard and excessively smooth1 or1 as it is sometimes expressively described1 without tooth4 ,as can easily be seen1 this is far from an ideal printing surface4 ,white also plays a prominent and effective part in many designs1 and is frequently indispensable4 ,its presence1 when necessary in ,direct ,tin ,printing1 must therefore be arranged for in some form or other4 ,one white printing is seldom sufficient to produce a perfectly clean and solid ground4 ,two printings1 or even three1 may be necessary4 ,purity of tone is a most important point1 and therefore a pigment should be chosen which will not only remain unchanged by its contact with the metal1 but which will be unaffected by the heat applied during stoving4 ,the appearance of this white may be improved by the addition of blue1 as in ,transfer ,printing 7p4 #gj71 and here also the smallest possible quantity will be sufficient4 ,gold ,lacquer ,printing is peculiar to ,tin-plate ,decoration1 and its advent indicated a vast progress in artistic display and effect4 ,printing lacquer is a transparent pigment of about the same consistency and character as printing ink4 ,it is usually prepared in three shades of colour--red1 citron or orange1 and pale gold4 ,a combination of these in suitable proportions will produce almost any strength or shade of gold which may be required4 ,except as regards their unusually brilliant transparency1 these lacquers much resemble yellow lakes1 and in paper printing might even be used as economical substitutes for the more expensive pigments4 ,this1 however1 is only a suggestion1 and has little if any practical bearing upon their application to ,tin-plate ,printing1 where they completely transform the bright sheen of the highly polished metal plate into a brilliant and most effective gold4 ,gold lacquer is an exceptional pigment in many respects4 ,it works exceedingly well1 and gives a sharp1 flat impression where most other pigments would fail4 ,it also has the power of conveying many of its own good qualities to any printing ink with which it may be incorporated4 ,in ,transfer ,printing the question of rapid drying is very important1 and in ,direct ,tin ,printing it is even more so4 ,arrangements of a somewhat extensive character must be made for the reception of metal plates immediately after printing1 so that the air may freely circulate about them1 and thus assist in the drying4 ,the room in which the printing sheets are thus stored must be free from dust1 for it will readily adhere to the tacky printing ink1 and afterwards prove a source of endless trouble4 ,illustration3 ,,fig4 #bf4 ,drying racks of various descriptions are used for the storage of printed metal plates4 ,one of the best is constructed on the lines shown in ,fig4 #bf4 ,the shelves ,a ,a are adjustable so as to carry plates of different sizes4 ,the printed sheets are set up on end in the grooves ,b ,b1 and by arranging them back to back in pairs a large number can be accommodated without hindering the drying4 ,other types of drying racks are shown in the sectional drawings 7,figs4 #bg;,a and #bg;,b74 ,illustration3 ,,fig4 #bg;,a4 ,the question of air-drying versus stoving has ever been a contentious one1 and admits of considerable diversity of opinion4 ,air-drying is preferable where convenient4 ,it is much more economical than stoving1 of course2 but1 on the other hand1 it might be a better plan to stove a printing than to wait1 perhaps for some hours1 until it dried naturally4 ,with some printing inks and under certain climatic conditions both may be necessary1 so it is almost impossible to lay down any hard-and-fast rules as to the adoption of either plan4 ,illustration3 ,,fig4 #bg;,b4 ,some knowledge of their respective disadvantage should be acquired1 however1 in order to avoid1 or at least minimise1 them4 ,illustration3 ,,fig4 #bh4--;,convenient method of stacking decorated metal plates to distribute their weights and prevent injury4 ,take1 for instance1 a course of eight printings1 each one absolutely necessary to the design1 and each one to be dried by stoving4 ,it is only reasonable to suppose that the first and second printings will be seriously affected by the subsequent stovings4 ,they will undoubtedly harden to such an extent as to render the super-position of other colours a difficult matter1 and their purity of tone will most probably be affected4 ,according to the same line of reasoning1 some sheets would be more affected by the heat than others1 owing to their position in the racks1 the heat of stoves being greatest near the top4 ,air-drying can only be accomplished by adding to the printing ink a proportion of some suitable drier4 7,see ,transfer ,printing1 p4 #ga47 ,naturally1 it requires a much longer time1 but it is equally effective1 much less troublesome1 and generally more satisfactory4 ,,chapter ,,xiv ,,tin-,,plate ,,decoration ,suitable ,designs--,a ,variety of ,effects--,gold ,lacquer-- ,super-position of ,colours--,embossed ,effects--,embossing ,plates--,lacquers4 ,it is usually and rightly supposed that the most effective results in ,tin-plate ,decoration are produced from designs which are lithographed for that specific purpose4 ,designs which are specially arranged for ,paper ,printing can be used so long as the effect produced by the transposition from right to left does not affect its application1 or render the same impossible4 ,this1 of course1 applies more particularly to designs in which lettering appears1 but at the same time it may affect designs of an essentially pictorial character in an equally important manner2 for it must be remembered that a drawing for ,tin-plate ,printing must appear on the lithographic stone exactly as it is impressed on the metal1 and not1 as in ,paper ,printing1 reversed from right to left4 ,this naturally simplifies the drawing on stone1 and to some extent enables the draughtsman to dispense with the reversing mirror when copying4 ,the primary object of this short chapter will be to point out some of the characteristic features of ,tin-plate ,decoration1 so that such methods as are usually adopted by the artist and the printer may be modified or amplified to meet any peculiar requirements of work in hand4 ,a greater variety of effects can be attained on the polished metal plate than it is at all possible to produce on paper4 ,a gold effect1 the result of lacquer printing1 is especially striking4 ,in a similar manner an excellent translucent lustre can be imparted to almost any colour by taking away the white opaque ground1 and thereby producing a peculiar semi-transparency which is both pleasing and effective4 ,lacquer printed over white produces a buff colour1 which can be used as a second yellow or to form the base of a flesh4 ,the colour of the lacquer is softer and less obtrusive when printed under instead of above the white4 ,the super-position of colour generally1 as described in ,chap4 ,,xii4 page #gj1 is peculiar to tin-plate printing1 and suggests the advisability1 if not the necessity1 of a special design4 ,the advantages of such super-position are obvious and substantial4 ,under ordinary commercial conditions it is almost impossible in tin printing to obtain the same intensity of tones in the printed colours as in paper printing4 ,some such strengthener as the super-position of suitable colours is therefore necessary4 ,the work of the lithographic draughtsman is in this respect of a somewhat unusual character2 but a little intelligent consideration will render its execution on these lines comparatively easy and satisfactory4 ,as already stated1 yellows can be accentuated by a super-position of lacquer1 and in the same manner blues and greys add intensity to black4 ,red can be strengthened by a foundation of lacquer1 also flesh and yellow1 either singly or in combination4 ,the drawing of lacquer and white formes should receive the most careful attention4 ,they should fit each other accurately1 even to the most minute details2 for the slightest overlapping will be revealed by the presence of a very assertive buff colour1 while any deficiency in combination will leave a not less striking margin of bright tin exposed4 ,in some instances it might be an advantage to transfer one forme from black to white to produce the opposite colour1 and thus ensure perfect register4 ,in decorative designs particularly1 tin-plate printing suggests almost unlimited possibilities for brilliant effects1 and in this respect it offers fair latitude for individual originality and manipulative skill4 ,in the production of show tablets especially1 considerable attention has been given to embossing1 in order to suggest and represent relief4 ,though not actually produced by the artist1 this is in effect part of the scheme or plan of his design1 and will consequently influence his work to some extent4 ,for simple ornamentation only1 metal embossing presents little that is new or novel2 but for the production of relief effects in the pictorial elements of a design its application becomes a more important and influential matter4 ,by its aid a flat and otherwise uninteresting subject can be made attractive and vigorous1 and for general purposes of effective display its value will be considerably enhanced and its assertive character emphasised4 ,without entering too minutely into matters which affect the lithographic printer in an indirect fashion only1 it will yet be useful to him to know how an embossing die is produced which registers accurately with the design to be operated on4 ,a black impression of the outline forme of the design is made on transfer paper similar to that described in ,chap4 ,,xii4 page #fh1 and re-transferred1 by pressure only1 to another sheet of the same paper4 ,the re-transfer is to be the impression required1 and this in its turn is re-transferred again to a prepared brass plate4 ,the only preparation necessary is the levelling and planing of the plate1 and1 if desired1 it can be coated with a thin layer of white paint or enamel4 ,this white ground makes the work easier1 by rendering the impression more distinct4 ,with such a guide as this the cutting or engraving is a comparatively simple matter4 ,the engraved plate is placed in a casting box1 and a stereo-metal casting is made from it4 ,a little trimming may be necessary for the completion of these two tools1 and they will require to be suitably mounted1 so that they may be accurately adjusted in the embossing press4 ,metal embossing has certain limitations which must be recognised as an essential condition of its effective application4 ,the plates vary considerably in texture and temper1 and the depth and character of relief will1 to some extent at least1 be controlled by the quality of the metal4 ,sharp lines and abrupt terminations impose a strain under which many plates split1 therefore such features ought to be avoided4 ,easy1 rounded lines1 rather than those of the straight furrow description1 produce the best results and give least trouble during operations4 ,where abrupt terminations are quite unavoidable the design should1 if possible1 be so arranged as to evade the super-position of colour over these parts4 ,lacquer1 if properly mixed and applied1 is probably the toughest pigment used by the tin printer1 and is generally suitable for embossed work4 ,it prints an exceedingly thin layer or film on the face of the metal1 which under average conditions rarely interferes with the working of the embossing tool4 ,,chapter ,,xv ,,photo-,,lithography ,early ,experiments--,an ,analysis--,the ,direct ,process-- ,transfer ,process--,line and ,half-tone--,some ,difficulties-- ,a ,natural ,grain--,ink ,photo-screen ,effects--,essential ,features4 ,one of the most promising features of lithography is its co-partnership with photography as a rapid and accurate method of reproduction4 ,the resources offered by this combination are very extensive4 ,for facsimile copying and proportionate enlargement or reduction photography stands unrivalled1 and1 although in certain phases it may be somewhat mechanical in its effects1 its relation to lithography as a reproductive art is nevertheless of an intensely practical nature1 and far from inartistic in character4 ,the first idea of inking up a photographic print so that it might be transferred to the lithographic stone was suggested in the simplest possible manner4 ,a brief account of its inception will be instructive as well as interesting1 inasmuch as it will lead to a clearer conception of the elementary principles involved4 ,during the early experiments in carbon printing it was discovered that a gelatinous film sensitised with certain bichromates could be charged with a coloured pigment1 and a picture developed thereon4 ,at first it was not realised that images produced by the action of the light on such a surface could be inked up with a greasy composition and afterwards transferred to the lithographic stone1 but it was not long before this important point became apparent4 ,it was found that after exposure under the negative the transfer ink would only adhere to such portions of the gelatinous surface as had been acted upon by the light4 ,photo-lithography will best be considered under two sections1 namely3-- #a4 ,the direct process1 in which the actual printing surface is prepared and exposed under the negative4 #b4 ,the transfer process1 in which a gelatine-coated paper is sensitised in a solution of bichromate of potassium and the photographic print made upon it4 ,the direct process in its application to the lithographic stone is uncertain in its results4 ,it is impossible to secure sufficiently close contact between the negative and the stone1 particularly when large surfaces are under operation1 and consequently the print is rarely if ever an unqualified success4 ,the erasure of defective work is also a serious matter1 and can only be effected by polishing and preparing the stone again4 ,in the transfer process absolutely close contact can be assured by the use of the transfer paper2 and should the print from any cause whatever prove defective1 another can be made immediately without any serious loss of time or material4 ,the successful application of the direct process to zinc and aluminium plates is1 however1 an accomplished fact4 ,the metal plate is sufficiently elastic to adapt itself to any inequalities on the surface of the negative4 ,under such conditions as these this process offers at least one very important advantage4 ,there is not the slightest possibility of distortion such as might occur in the development of a transfer4 ,the metal plate also lends itself to easy manipulation4 ,photo-lithography in line is simply the reproduction of line drawings or prints in which the design is represented in black and white with only such gradations as may be suggested by lines or dots4 ,half-tone photo-lithography is the reproduction of a design or copy which has in its composition gradations of tone in the form of flat tints4 ,it is sometimes described as the translation of the graduated light and shade of the original copy into a surface which can be printed from by mechanical means1 for which purpose the ink-bearing surface is broken up into the most minute sections1 and thus forming an almost imperceptible grain4 ,the first attempts to reproduce the half-tones of a copy1 in the form of a grain consisting of minute dots of varying size and contiguity according to the gradation of tone required1 were made with a screen of open textile fabric4 ,this screen was placed between the lens and the sensitive plate1 but the results were crude and unsatisfactory4 ,the invention of cross-lined screens1 in which the lines were cut on glass and filled with black or other suitable colouring matter1 was a decided advancement in the half-tone photo processes4 ,the screeny effect produced by the unvarying uniformity of grain in half-tone work is undoubtedly the chief drawback to its more extensive adoption for photo-lithography4 ,fine etching cannot be resorted to as in photo-engraving1 neither is it possible1 to emphasise effects by skilful overlay and underlay2 consequently half-tone impressions from a lithographic stone are frequently disappointing4 ,there are no insurmountable obstacles to hinder the production of excellent transfers1 nor is it a difficult matter to transfer them to stone4 ,the trouble is1 as already pointed out1 the unvarying uniformity of the grain4 ,this effect1 or rather this lack of effect1 has been to some extent overcome by the use of a four-line screen in lieu of the usual crossed screen1 but even this is merely a remedy and not a cure4 ,it has been confidently asserted that the highest degree of excellence in photo-process work will be attained by the adoption of what may be termed a natural grain4 ,several processes have been introduced which are undoubtedly based upon collotype methods in which a reticulated grain is produced more or less suitable for lithographic printing4 ,unlike the mechanical screen grain the texture of these processes reproduces the original copy with but little1 if any1 loss of expressive power4 ,this is indeed a feature of considerable importance1 and suggests many possibilities in the way of artistic reproduction4 ,to reproduce an old chalk drawing so that it might be successfully transferred to stone and printed in the usual way1 would be practically impossible by any other process4 ,in copying through a ruled screen many of the delicate contrasts of light and shade would be so reduced as to become almost valueless1 consequently the print loses both in artistic and expressive power4 ,in contradistinction to this a natural grain exhibits no harshness or indistinctness in the gradations of tone1 and retains its clearness and sharpness throughout the printing operation4 ,reverting again to the half-tone ruled screens1 it may be well to state that small prints1 being usually subjected to a closer inspection than large ones1 must be reproduced with great attention to the finer details to ensure a certain amount of fidelity1 and for this reason a screen with fine rulings must be employed4 ,naturally1 stronger and more vigorous reproduction can be secured with the coarser rulings1 but the screen effect will be too pronounced for close scrutiny4 ,there is still much to achieve in photo-lithography1 and it is probably owing to a full recognition of this fact that the progressive character of the process is maintained4 ,its commercial value is undoubted1 and its successful application is chiefly a question of how and where it can be most effectively introduced4 ,the essential features of photo-lithography are3-- #a4 ,a copy or original in which the modelling is well defined1 and the light and shade well emphasised1 even to a point of slight exaggeration4 #b4 ,a negative in which the whites of the original appear opaque1 with clear glass to represent the lines and solids4 #c4 ,a print which can be developed or inked up with a pigment sufficiently greasy in nature to transfer to the lithographic stone4 ,,chapter ,,xvi ,,photo-,,lithography--continued ,the ,copy--,gradations of ,tone--,scraper ,boards--,description and ,effect--,shading ,mediums--,crayon ,drawings--,half-tone ,copy4 ,it has already been pointed out that well-defined modelling is most desirable in the original copy4 ,to secure this a considerable degree of artistic perception and discretion1 as well as manipulative skill1 is requisite4 ,in photo-process work it is almost impossible to produce artistic effects from an indifferent or unsuitable copy4 ,pen-and-ink sketches and wash drawings are entirely under the control of the artist1 and characteristic effects are chiefly due to bold and vigorous conception and skilful drawing4 ,few photographs are suitable for photo-mechanical reproduction without some previous preparation4 ,accentuation or modulation of the high lights and shadows will in all probability be necessary to secure a sufficient contrast of light and shade4 ,the middle tints may require but little attention1 unless it be to work down any tendency to abruptness in the gradations of tone4 ,a bold and well-defined silver print usually copies well when clamped between two pieces of glass to take out the grain1 and photographed by artificial light4 ,scraper boards offer most remarkable possibilities for black and white and half-tone sketches4 ,a careful examination of ,fig4 #bi will serve to demonstrate their peculiar fitness for process drawing4 ,a light wood pulp board forms a convenient base upon which a thick coating of white composition is laid4 ,black ruled lines are printed on this surface1 and lines of a similar texture are embossed at right angles to them4 ,some of the characteristic effects which can be produced on this board by the use of the crayon and scraper are suggested by ,nos4 #f and #g1 ,fig4 #cj4 ,no4 #h gives a stipple which is both printed and embossed4 ,no4 #i is a plain board upon which pen-and-scraper effects alone are produced4 ,drawings in pen and ink1 on ,nos4 #aj and #aa patterns1 may be effectively handled by a free and skilful use of the scraper4 ,embossed lines only are the peculiar features of these boards1 but variety of texture can be obtained by scraping these lines into dots4 ,scraper board sketches almost invariably represent a maximum of effect with a minimum of work1 and for this reason alone such an adaptable and simple medium should soon win its way into general favour4 ,their merit1 however1 is not confined to this one point4 ,they provide almost unrivalled copy for photo reproduction1 and can therefore be applied to a variety of purposes4 ,even a cursory glance at the scraper board sketch on page #ia will reveal many points of interest and value which a more careful scrutiny can scarcely fail to emphasise4 ,small patches of scraper boards can be introduced into process drawings of any description1 and brilliant results be secured thereby4 ,in such a manner clouds1 waves1 foliage1 and a variety of other effects can be introduced4 ,shading mediums are already well known to lithographers1 yet it is doubtful if their usefulness for the amplification of sketches or process drawings is fully appreciated4 ,they offer almost endless combinations of texture and tint1 and are therefore most useful and valuable accessories in the hands of a resourceful artist4 ,illustration3 ,,fig4 #bi4--,reproduction of a drawing made on ,gilby ,hermann's scraper boards4 ,illustration3 ,,fig4 #cj4--,some scraper board textures4 ,many artists favour crayon work on a grained paper1 adopting a broad sketchy treatment in liberal proportions1 so that in the subsequent reduction the freedom of the original will be toned down just sufficiently to enhance the picturesque and artistic value4 ,drawings made on scraper boards1 grained papers1 or by the aid of shading mediums1 are photographed and reproduced by the ordinary line method4 ,in making sketches for half-tone photo-mechanical reproduction it must be remembered that1 as far as photo-lithography is concerned1 it is impossible to accentuate effects by what is known as fine etching when applied to photo-engraving4 ,a negative for photo-process work of any description should be absolutely perfect in every respect4 ,the whites of the copy in the negative should be of an absolutely opaque black1 showing clean1 sharp edges1 with clear glass representing the lines1 dots1 etc4 ,these are all-important factors1 and their influence upon the reproduction of the original can scarcely be over-estimated4 ,,chapter ,,xvii ,,photo-,,lithography--continued ,a ,copying ,table--,exposure--,illumination--,photo -litho ,transfers--,the ,paper--,printing--,developing--,a ,direct ,process4 ,to discuss the respective merits of the wet collodion1 collodion emulsion1 and dry-plate processes lies beyond the province of this work1 as does also a detailed description of the operations involved4 ,the processes are purely photographic1 and have already been presented to the craft in various forms4 ,it is1 moreover1 almost impossible to bring within the limits of a single chapter anything approaching to a comprehensive record of the multitudinous details upon which process photography is based4 ,all that can be attempted is to take one or two outstanding features which suggest a few useful hints4 ,the original or copy for reproduction must be on the same optical plane as the sensitive plate in the camera1 i4e4 they must be absolutely parallel with each other4 ,there are several ways of ensuring this4 ,the most convenient method is to use a copying table and board similar to ,fig4 #ca4 ,with such an arrangement as this direct copying can be attained through the lens1 or the camera can be turned half-way round1 and the image reversed by means of a mirror or prism attachment4 ,the chief advantage of such an arrangement is1 that the position of the camera can be altered at will without affecting the relative positions of the plate and copy4 ,illustration3 ,,fig4 #ca4 ,correct exposure and sufficient illumination of the copy are important factors in photographic reproductions of any kind1 but they are of infinitely greater importance when applied to photo-process reproduction4 ,one is1 to a certain extent1 dependent upon the other4 ,the former must of necessity be controlled by the latter2 yet no amount of exposure will compensate for defective illumination4 ,where artificial light is employed the advantage of using two lights is obviously great4 ,apart from the greater brilliancy and intensity of the light1 the illumination of the copy is more evenly distributed4 ,in scraper-board copies no shadows are thrown from the embossed dots or lines1 and the granular texture of grained papers is almost entirely eliminated4 ,a bichromated1 gelatine paper can be obtained by coating a hard writing paper of medium thickness with a gelatinous solution consisting of #a oz4 of gelatine and #a oz4 of water1 and afterwards sensitising it with bichromate of potassium4 ,it is advisable1 however1 to use the commercial varieties of coated paper1 and to sensitise it as it is required4 ,the sensitising solution can be prepared by dissolving #a oz4 of bichromate of potassium in #bj fluid oz4 of water4 ,add to this sufficient ammonia to give it a bright orange tinge4 ,keep this solution at a temperature of #fj ,fahr41 and float the paper on it for about one minute4 ,pin or clip the paper to a board or squeeze it to glass1 and dry in a dark room4 ,print this paper under the negative in a diffused light until the design appears in a rich golden-brown colour1 when the exposure may be regarded as sufficient4 ,the time allowed for such an exposure will1 of course1 vary according to the quality of the negative and the intensity of the light4 ,a development of the print may now be proceeded with in the following manner4 ,thin down a little transfer ink with turpentine and distribute it evenly on a composition roller4 ,roll up the print until it is completely covered with an exceedingly fine film of ink1 after which allow the turpentine to evaporate4 ,immerse the transfer in tepid water for about #aj minutes1 and then rub it gently with a piece of cotton lint previously soaked in water1 until the superfluous ink is removed and the design stands out clean and sharp4 ,the transference of the print to stone can be accomplished in the usual lithographic manner4 ,the chief points to be observed are1 to allow sufficient time for printing1 and to ink up the transfer with the thinnest possible film of ink4 ,a photo print can be made direct on the zinc or aluminium plate1 and by a slight modification of the photo-engraving process it can be developed according to lithographic methods4 ,it is impossible to introduce an intermediate process without1 in some manner at least1 depreciating the quality of the work4 ,in a direct photo print on zinc1 or1 in fact1 on any suitable printing surface1 the finer qualities of the work are much more likely to be retained than when a transfer print is made under the negative and afterwards transferred in the usual manner4 ,coat a finely grained zinc plate with sensitised asphalt solution and expose it under a negative for about #d-a_/b minutes in direct sunlight1 and from #ab to #ae minutes in a diffused light4 ,the action of light on the asphalt solution is to render it insoluble in turpentine1 so that if a sufficiently exposed plate is immersed in pure turpentine the lines1 etc41 of the design1 being of course represented by clear lines in the negative1 will remain intact1 while the surrounding portions will be dissolved and washed away4 ,after development wash the plate freely in water1 and dry it by fanning or with a pair of bellows4 ,let it stand for about #aj minutes and then slightly etch it with a very weak solution of nitric acid4 ,cover the work with strong1 fresh gum1 and dry it thoroughly and quickly4 ,remove the gum and rub up the design with black ink in the usual way4 ,wash1 dry1 and dust over with ,french chalk4 ,the plate can then be prepared in the manner described in ,chap4 ,,xi4 page #fa4 ,,the ,,end ,,index ,,page ,adjusting pressure in machine1 #ch ,adjusting stones in machine1 #cg ,air drying--tin printing1 #gh1 #gi ,alum1 #bg ,aluminium plates1 #eg ,aluminium plates-- ,alterations1 #fb ,direct photo1 #eh1 #he1 #ajj ,etching1 #fa ,machining1 #fe ,printing bed1 #fe ,rolling up1 #fj ,sensitising1 #ii ,transferring1 #ei ,aluminium rotary machine1 #fe1 #ff ,american printers1 #ec ,asphalt solution1 #ajj ,bavarian limestone1 #a1 #b ,blocking out1 #ed1 #ee ,blue tinge1 #gj1 #gg ,boxwood scraper1 #bj ,brake cylinder1 #ch ,bronze printing1 #di ,cam motion1 #ba ,canada balsam1 #ed ,castor oil1 #bh ,cause and effect1 #b ,ceramic decoration1 #ee ,chalk drawings1 #be1 #bf ,chemical affinity1 #b ,clean stones1 #c ,cohesion in printing ink1 #ed ,colour and design1 #dh ,changes1 #gj ,mixing1 #cj ,printing1 #dg ,registration1 #dh ,sequence1 #dh1 #ej1 #gf ,super-position1 #dh1 #ha ,transparencies1 #ee ,colours1 standard1 #ee ,copperplate press1 #ag ,printing1 #ag-ai ,stove1 #ah ,copy1 photo-litho1 #hi ,copying table1 #if ,crayon or chalk drawing1 #h ,crayon work1 #hi1 #ij ,cylinder press1 #ba ,damping rollers1 #dj ,design1 #bd ,design1 inverted1 #fh ,design1 suitable1 #hj ,development1 photo print1 #ii ,direct impression1 ,a1 #gb ,discoloration1 #gj ,distortion1 #di1 #fh1 #ge ,dryers1 #ga ,drying colours1 #ej1 #ga ,drying metal plates1 #gg1 #gh ,drying racks1 #gh1 #gi ,duplication of design1 #cj1 #ca ,effect of pinks and greys1 #di ,effects in tin-plate printing1 #ha ,elastic bedding1 #bb1 #bc ,electricity1 #df ,elements of lithography1 #b ,embossed lines1 #hi ,plates1 #hb ,embossing dies1 #hb1 #hc ,enamelled paper1 #ea ,etching1 #be1 #bf ,evolution of tin-plate printing1 #fg ,exposure1 #ii ,fine etching1 #ie ,french chalk1 #ga1 #gf ,skins1 #bh ,friction glazed paper1 #ea ,glass muller1 #f ,gold lacquer1 #gg1 #ha ,gold printing1 #di ,grain1 natural1 #hg ,graining stones1 #e1 #f ,grinding stones1 #d-f ,gripper1 #db ,gripper margins1 #ca ,grit1 #dc ,half-tone1 photo-litho1 #hf ,halligan machine1 #cd-cf ,hand labour and machine1 #c ,lever1 #ba ,roller1 #bh ,high lights1 #hi ,homogeneity of stones1 #b ,illumination of copy1 #ii ,impression1 #bg ,impression1 size of1 #ge ,impression1 solid1 #df ,inking rollers1 #ci ,inks1 printing1 #eb-ef ,tin-plate printing1 #fi-ga ,transfer1 #h-aa ,inverted design1 #fh ,key formes1 #bg1 #da ,lacquer1 peculiar feature of1 #hc ,lacquer1 tin-plate1 #gg ,lamp-black1 #bh ,leather dressing1 #bb ,level surfaces1 #c ,levelling stones1 #cg ,line1 photo-litho1 #he ,linoleum1 #bc ,linseed oil1 #eb1 #ec ,litho press for copperplate1 #ai ,litho press1 mechanical principles1 #bj1 #ba ,litho press1 pressure1 #bj ,litho varnish1 #eb1 #ec ,magnesia1 #ga ,mechanical affinity1 #b ,metal plates1 #eg ,method1 #de ,modification of colour sequence1 #dh ,motor driving1 #df ,nap roller1 #bh ,natural grain1 #hg ,negative1 #hh ,offsets1 #bg1 #bh ,oriental blue tinge1 #gj1 #gg ,original stones1 #cj ,outline forme1 #dh ,packing cylinder1 #ba ,paper1 enamelled1 #ea ,well seasoned1 #di-ea ,pen and ink sketches1 #hi ,pen and scraper effects1 #ij ,photo litho-- ,copy1 #hi ,development1 #ii1 #ajj ,direct1 #he ,half-tone1 #hf ,inception of1 #hd ,line1 #he ,printing1 #ii ,transfer1 #he ,transfer paper1 #ii ,plumbago1 #bb ,porosity of stones1 #b ,preparation of stones1 #b-g ,preparing designs1 #bd1 #be ,pressure alterations1 #dc ,excessive1 #cg ,litho press1 #bj ,peculiarities1 #ge1 #gf ,printing inks1 #eb ,cohesion of1 #ed ,printing medium1 #a ,proving1 #bi1 #cj ,recipes1 transfer inks1 #i-aa ,transfer papers1 #ac-ae ,reciprocal movement1 #gb ,reducing medium1 #ec1 #ed ,register lines1 #bi1 #cj ,registration1 #bi1 #da ,registration of colour1 #dh ,remedy1 ,a1 #ga ,re-transferring1 #ca ,rotary machine1 printing1 #fe1 #ff ,rubber blanket1 #gb-ge ,resilience of1 #gf ,scraper1 #bj-bb ,scraper boards1 #hi1 #ij ,scratches1 #e ,screen effect1 #hf ,screen photo1 #hf ,senefelder1 #b ,sensitising solution1 #ii ,sequence of colour1 #dh ,set off1 #ga ,shading mediums1 #ij ,shadow1 #hi ,sheen of metal plate1 #gj ,side lay1 #db ,silver print1 #hi ,slogger1 #ch ,sludge1 #e ,solid oil1 #ec ,speed1 #cf1 #cg1 #df ,speed cones1 #df ,standard colours1 #ee ,stone-planing machine1 #c1 #d ,stone-polishing machine1 #d1 #e ,stoving tin-plates1 #gh ,transferred prints1 #fi ,substitutes for stone1 #eg ,suggestion1 ,a1 #di ,super-position of colours1 #dh ,tooth of grained stones1 #g ,of metal plates1 #eh ,transfer inks-- ,active principle of1 #h1 #i ,copperplate1 #aj1 #aa ,extra powerful1 #aa ,plate1 #i ,stone to stone1 #aj ,writing1 #i1 #aj ,transfer paper-- ,autographic1 #ad ,copperplate1 #ad1 #ae ,diaphanic1 #af ,grained1 #ae1 #af ,photo-litho1 #af1 #ii ,specific value of1 #ab ,stone to stone1 #ac ,transparent1 #ac1 #ad ,varnished1 #ac ,transfer printing1 #ee ,transferring1 #cb1 #cc1 #ajj ,transparencies1 #ee ,trimming paper1 #dc ,tympan1 #ba1 #bb ,v-shaped edge1 #bb ,varnish1 litho1 #eb1 #ec ,vaseline1 #ed ,venetian red1 #bh ,water of ,ayr stone1 #be ,white printing1 #gj1 #gf1 #gg ,zinc plates1 #eg ,zinc plates-- ,alterations1 #fb ,de-polishing1 #eh ,etching1 #fa ,graining1 #eh ,machining1 #fe ,photo1 direct1 #eh1 #he1 #ii ,printing bed1 #fe ,rolling up1 #fj ,sensitising1 #ii ,transferring to1 #ei ,printed by ,,morrison ,,gibb ,,limited1 ,edinburgh 99 99 99 99 99 ,transcriber's ,notes3 ,obvious punctuation errors were repaired4 ,both overestimate and over-estimated appear in the original text4 ,the following additional corrections were made to the text3 ,page #df1 therein changed to herein 7are discussed herein which17 ,page #dh1 superposition changed to super-position 7the super-position of blues17 ,page #gj1 word the added to text 7,at the same time17 ,page #ajb1 #ab changed to #a1 #b 7,bavarian limestone1 #a1 #b7 ,page #ajb1 discs changed to dies 7,embossing dies1 #hb1 #hc7 ,page #ajc1 #fa changed to #ea 7,paper1 enamelled1 #ea7 ,page #ajd1 #d changed to #aa 7,extra powerful1 #aa7 ,page #ajd1 ,depolishing changed to ,de-polishing to match text 7,de-polishing1 #eh7