LITHOGRAPHY. The principle upon which the art of lithography is based is very simplethe antagonistic qualities of grease and water. An unctuous composition is made to adhere to a peculiar kind of limestone; the parts thus covered acquire the power of receiving printing ink; the other parts are prevented from receiving it by the interposition of a film of water; and then by pressing paper strongly upon the stone impressions are obtained. There are two distinct branches in lithographydrawing and printing. Those practising the first are known as lithographic draughtsmen or writers, the second as litho-graphic printers.
The art of lithography was discovered by Alois Senefelder, a native of Prague, born 6th November 1771. His father, Peter Senefelder, was one of the performers of the Theatre Royal at Munich. The son Alois wished to follow the same profession, but, his father being opposed to this, he went to the university of Ingolstadt, and devoted himself to the study of jurisprudence. Owing to the death of his father shortly afterwards, he was unable to continue his studies at the university, and, yielding to his old inclination, he tried to support himself as a performer and author, but without success. In order to accelerate the publication of one of his works, he frequently spent whole days in the printing office, and thus became acquainted with all the particulars of the process of print-ing. It appeared so simple that he conceived the idea of purchasing a small printing press, thus enabling himself to print and publish his own compositions ; but his means were inadequate, and to this circumstance we probably owe the invention of lithography. Unable to pay for the engraving of his compositions, he attempted to engrave them himself. He tried numerous experiments with little success ; tools and skill were alike wanting. Copper-plates were expensive, and the want of a sufficient number entailed the tedious process of grinding and polishing afresh those he had used. About this period his attention was accidentally directed to a fine piece of Kellheim stone which he had purchased for the purpose of grinding his ink. His first idea was to use it merely for practice in his exercises in writing backwards, the ease with which the stone could be ground and polished afresh being the chief inducement. The idea of being able to take impres-sions from the stone had not yet occurred to him. While he was engaged one day in polishing a stone slab on which to continue his exercises, his mother entered the room and desired him to write her a bill for the washer-woman, who was waiting for the linen. Neither paper nor ink being at hand, the bill was written on the stone he had just polished. The ink used was composed of wax, soap, and lamp-black. Some time afterwards, when about to wipe the writing from the stone, the idea all at once struck him to try the effect of biting the stone with aqua fortis. If the parts written on resisted its action, impressions might then be taken in the same way as from wood engravings. Surrounding the stone with a border of wax, he covered its surface with a mixture of one part of aqua fortis and ten parts of water. The result of the experiment was that at the end of five minutes he found the writing elevated about the tenth part of a line (-J-IQ-inch). He then proceeded to apply the printing ink to the stone, using at first a common printer's ball, but soon found that a thin piece of board covered with fine cloth answered better, communicating the ink more equally. He was able to take satisfactory impressions, and, the method of printing being new, he hoped to obtain a patent for it, or even some assistance from the Government. For years Senefelder continued his experiments, until the art not only became simplified, but reached a high degree of excellence in his hands. In later years the king of Bavaria settled a handsome pension on Senefelder. He died at Munich in 1834, having lived to see his invention brought to comparative perfection.
Materials Employed by the Lithographic Artist. ---Litho-graphic stones are very compact homogeneous limestones, imported chiefly from Germany. The traffic has its centre in the village of Solenhofen, in the district of Monheim. The Solenhofen stone, in its chemical decomposition, con-sists of lime and carbonic acid. It is generally cut in slabs from 2 to 3 inches in thickness, and is sold by weight. Stones yielding impressions in the lithographic press have been found in England, France, Italy, Canada, and the West Indies; but all are much inferior to the best German stones. Lithographic stones vary in colour from a dull grey or yellow to a light creamy shade, the dark grey stones being the hardest. They are sometimes uneven in colour, having light and dark patches. These are suitable for ordinary transfer work; but, in cases where the artist requires to see the effect he is producing during progress (as in chalk drawing), stones of an even grey or drab colour should be selected.
Lithographic ink is composed of tallow (4 oz.), wax (5 oz.), soap (4 oz.), shellac (3 oz.), and quant, suff. of fine Paris black. The inks of Lemercier and Vanhymbeeck are generally considered as among the best. Lithographic chalk is made in the same manner as the ink, but requires to be burnt sufficiently hard for use in drawing. Excellent lithographic crayons are manufactured by Lemercier of Paris. They are made of several degrees of hardness, copal chalk, used for outlining, being the hardest.
Transfer paper for writing and drawing is prepared by coating the surface of the paper with a composition of size, made from parchment cuttings and flake white. Some-times the coating is composed of starch and glue. Colouring matter, generally gamboge, is added, the object being to show more readily which is the coated side of the paper. The coating is applied with a full brush. For writing, the paper used is thin, for drawing it is thicker; for large subjects ordinary drawing paper is used. It is afterwards glazed by being pulled through the lithographic press, face down, on a smooth stone, or hot pressed. There are several other varieties of transfer papersa transparent or tracing paper, and a transfer paper for chalk drawing, hav-ing a finely granulated surface. Mr Nelson of Edinburgh patented a method of graining transfer paper by means of stippled plates. The older method was to press the coated surface of the paper on an ordinary sand-grained stone or plate.
Instruments and Appliances used in Lithographic Draw-ing and Writing.For the finer purposes of lithography ordinary steel pens are useless: " Perry's lithographic pen " may be found serviceable when the work is not very delicate. Transfer writers prefer pens of their own mak-ing. These are either made from quills scraped down, before cutting, with a piece of broken glass, until the barrel yields to pressure of the nail, or cut with a pair of sharp scissors from thin sheets of steel prepared for the purpose. This operation is difficult, and requires much skill and practice. Pens are aMo made of watch springs, reduced to the necessary tenuity by nitric acid and water.
Lithographic brushes are made from red sable crowquill pencils ; a portion of the hair is cut away all round, and, only the central part of the brush is used.
Scrapers are employed in correcting the work upon stone, but a penknife or ordinary erasing knife answers the pur-pose equally well.
Crayon holders of the ordinary kind may be used for lithographic chalk. When cut in two and fitted with a wooden handle, they will be found lighter and pleasanter to work with.
The hand-board is a piece of wood about 6 inches wide, three-eighths of an inch thick, and somewhat longer than the stone on which the draughtsman works. It rests upon thick strips of millboard fixed round the edges of the stone, to keep it from touching the part to be drawn on.
Ruling and circle pens, parallel rulers, tracing paper, a tracing point, and red tracing paper, for transferring, tracings to paper or stone, are also requisites.
Drawing on Stone.The Chalk Method.For artistic purposes this is perhaps the most important and interesting department of lithography. In preparing the stone for chalk drawing, the surface, instead of being polished, is j broken up into minute points or " grained." The coarseness or fineness of the grain is varied according to the work to ! be done. A hard stone, free from veins, marks, and chalk spots, and of a clear grey colour, is selected. It is first ground and pumiced to free it from scratches. A small quantity of the finest gravel sand, or " graining-sand," is sprinkled over the surface, and a few drops of water added; a smaller stone of the same size and hardness is placed above, face downwards, and moved about with a circular motion ; water is added from time to time, and fresh sand when needed. Care must be taken that no scratches are caused by grains of coarser sand finding their way to the stone; the stone is afterwards washed in clean water and dried, and the grain tested with a crayon. If it prove too coarse or too fine, or if scratches are dis-covered, the graining is done over again.
The drawing is then traced upon the stone. As it has to be reversed, the tracing is fastened face downwards ; red tracing paper is introduced between, and the outline care-fully gone over with a steel tracing point or a hard pencil. The tracing papers are then removed, and the surface of the stone protected with a sheet of plain paper. The hand-board is placed across to keep the warmth of the hand from causing the condensation of moisture resulting from its coming in contact with the paper covering the stone. The paper covering the part of the drawing to be first commenced is then removed. The crayons are pointed with the knife, cutting from the point upwards.
Great care and cleanliness are necessary to prevent injury to the work. If the artist wishes to talk he ought first to cover up the surface of the stone, as a drop of saliva falling upon it prevents the penetration of the chemical chalk, and a white spot will be the result when the drawing is " brought up " by the printer. If the stone is touched by greasy hands, the form of the fingers and of the skin will appear in black.
The drawing is commenced by outlining. For this pur-pose the hardest chalk (copal) may be used, but No. 1, when it will answer the purpose, is better. The " tinting " or shading follows ; lights may be picked out with the scraper or penknife, and ink used when sharp, dark touches are desirable. It is difficult to rectify mistakes ; prevention is better than cure. In reversing the drawing a small hand looking-glass will be found useful.
When completed the drawing is " etched." There are two different ways of applying the acidone by flooding the stone with nitric acid diluted with water, the other with acid diluted with gum-water, applied with a flat, soft brush about 4 or 5 inches in width. Although this opera-tion appears simple, it is not without risks; much of the success of the impressions depends upon it. If the stone is too strongly etched, the delicate tints and lines dis-appear ; if not etched strong enough, the drawing is apt to lose clearness, and run smutty in printing. When the etching is completed, the water is drained off and the stone gummed and allowed to dry. It may then be put into the hands of the printer for proving.
Pen and Brush Method.The surface of the stone is ground and afterwards polished with Water-of-Ayr stone or snake-stone. The drawing or writing is traced upon the surface in the manner already described. The principal drawback in this method is the necessity of reversing writ-ing and lettering, which cannot be done without consider-able practice. Its advantages over the transfer method scarcely compensate for the additional difficulties. The stone is etched as in chalk drawing before passing into the printer's hands.
Engraving on stone is chiefly useful in the reproduction of drawings by architects, civil engineers, &c. Its advant-ages are accuracy and sharpness in drawing and printing. A thin film of gum is spread on the surface of the stone, and when dry washed off; a dark ground is then laid on by rubbing in Paris black. Ked grounds also are sometimes used. The tracing, if on a black ground, is made with paper prepared with chrome yellow, if on a red ground with Paris black. The method of engraving is simple. The tools are strong needles, firmly fixed in cane handles, and good spring dividers ; the incised lines show white upon the black or red ground. When the work is finished they are filled up with fatty ink, and the stone cleared with water and a piece of coarse flannel.
In printing, the stone is damped in the usual way, but the ink is applied with a dabber instead of a roller.
Lithography on Paper, or Transfer Lithography.By this method the work is done on paper, and afterwards transferred to the stone. The paper has been already described, as also the instruments used in writing and drawing. The ink is prepared by rubbing a small quantity into a saucer of white delft or china, the saucer being first heated to make the ink adhere ; water is then added, and the ink rubbed with the finger till it dissolves. Care has to be taken to make it of the proper consistency. If pale and thin, it will not transfer properly; if too thick, it will not flow freely from the pen or brush, and will spread in transferring.
The paper should not be handled or touched, except at the edges. Finger marks from a moist or greasy hand will roll-up black. A piece of clean white paper is kept under the hand when working. The same line must not be gone over twice while wet, as the composition on the surface of the paper is apt to get mixed with the ink and destroy its qualities. In drawing on chalk transfer paper the crayon is used instead of the brush or pen. Dark touches may be put in with ink, and the lights picked out with the knife.
The stone for the reception of transfers is polished free from perceptible scratches, and is generally warmed to make it more susceptible of receiving the ink. The transfer is placed face downwards on the stone, pulled repeatedly through the press, and afterwards removed to the trough, where hot water is poured over it. It is then peeled off, leaving the ink and the composition on the stone; the latter is washed off, and the stone gummed and allowed to dry. The work is afterwards " proved " by rolling-up, cleaning, etching, and taking the first impressions.
The transfer method is also applied successfully to the reproduction by lithography of engraved plates, wood en-gravings, and type.
Photo-Lithography.By this method copies of prints or drawings executed in clear lines or dots can be produced. They may be either of the same or of altered dimensions. The copying is done by photography upon glass; but, as it is necessary that the negatives should have straight marginal lines, ordinary photographic lenses are not adapted for the purpose" rectilinear," " aplanatic," " symmetrical," and other varieties being used instead. The negative is put into a photographic printing frame, and a piece of sensitive transfer paper placed face downwards upon it, the glass side being exposed to the light. The time of exposure varies according to the intensity of the light and the quality of the negative. When sufficiently exposed it is carried into a dark room, the photographic print taken out of the frame, laid face downwards on a stone coated over with transfer ink, and pulled through the press. It is then soaked for a few minutes in water warmed to the temperature of 100°, and the inked side of the paper carefully sponged with gum-water to remove the transfer-ring ink from the parts upon which the light could not act. After being washed in warm water it is allowed to dry, and is then transferred to the stone and printed from in the usual manner.
Zincography so nearly resembles lithography in its principles that a very few words of explanation will be sufficient. Zinc plates possess the advantage of costing less and being much more portable than lithographic stones, and are easily cut into convenient sizes. They are grained in the same manner as lithographic stones, a muller of zinc being used instead of one of stone. Drawings on zinc, whether in chalk or ink, are executed on a grained surface. Zinc plates are subject to oxidation, and care must be taken to dry them off quickly after graining. The drawing is done precisely in the same way as on stone; the etching solution is applied with a flat camel-hair brush. It con-sists of a decoction of nut-galls; a solution of gum and phosphoric acid is sometimes added. During printing the plate is screwed for support to a block of beech or other hard wood. As neither crayon nor ink penetrates the zinc as they do the stone, the adhesion of the ink forming the drawing is less thorough than in lithography, and greater precautions have to be taken to prevent accidents in printing.
Chromo-Lithography.Great advances have been made in recent years in this branch of the art, notably in the reproduction of works of an artistic character. Its simplest form is the tint, in several gradations of one colour, printed over drawings in chalk or line; in its more elaborate forms it includes imitations of water-colour drawings, decorative and ornamental designs, &c. The term " chromo-litho-graphy " is usually applied only to the more elaborate kinds of colour printing.
All lithographs in two or more colours are printed from two or more stones. It is therefore necessary to employ some method to get a correct repetition of the subject on the first stone made upon the others, and to be able in printing to place the sheet so correctly in position that the second and each succeeding printing shall fall exactly into its place upon the first. Much of the success of the work depends upon this, and various modes of " registering," by "lay," by needles, by fixed points, &c, are employed. The first drawing is generally in outline. It is called the keystone, and provision is made in it for " registering," according to the particular method adopted by the artist. It is used only to take as many impressions on other stones as are required for the several colours, and as a means of getting each colour in its exact place. In work of an artistic character it is omitted in printing.
For ordinary colour printing the stone is polished; when gradation of colour is required the stone is grained, but in a somewhat coarser way than for chalk drawing. It will be sufficient here to describe the production of drawings with two tints. The principal drawing is done upon a grained stone in chalk, and should be very bold, more like a sketch on tinted paper, the middle and finer tints being left out. The stone is then etched, and two impressions are taken, so that when each of these is put upon a roughly-grained stone, and passed through the press, counter impressions will be found upon the stones, revealing the drawing quite distinctly. After having cut in the outlines with a sharp-pointed graver, or steel needle, the artist covers those parts on the two stones which are not to appear in the one or the other colour, as well as the margin of the two stones, with a brush containing acid and gum. The stones are then warmed, and a composition containing the same ingredients, as soft chalk, with double the quantity of soap, and three times the quantity of tallow, is rubbed over it with a bit of coarse flannel, until it is of a dark greyish-brown colour. From having been previously cut in, the outline comes out very distinctly. The artist can now produce an effect similar to crayon sketches which have been washed in with two separate colours. Those portions which have been rubbed in, and which appear dark greyish-brown, form the middle tint, and the scraper may be used to reduce the colour of the tint where the gradation of colour is desired,- the darkest portions being laid in with lithographic ink, and the blending together done with chalk, brush, pen, and scraper, so as to produce in many places the effect of shadings of one colour over another. When the work is of a very elaborate or complicated nature, the order in which the colours should succeed each other in printing is of much importance, and requires to be very carefully considered. In highly finished chromo-lithographs, fifteen or more printings are frequently necessary. Difficulties sometimes arise from the paper stretching, either from the moisture on the surface of the stone or from the action of the press.
Oleography differs from chromo-lithography only in name, and is a mere vulgar attempt to imitate oil painting. The finished print is mounted on canvas, sized, and varnished. The loaded colours and rough textures, if there happen to be such in the original, are suggested by embossing, with what result it is hardly needful to say.
Instruments, Tools, and Apparatus used in Printing.Litho-graphic presses are of a great variety of construction, and we can only glance at the chief points in their mechanism. The scraper is a wedge-formed plate of boxwood, fixed to the bottom of the platten ; its edge is covered with a piece of leather, and properly adjusted. The table on which the stone with the paper for receiving the im-pression is placed, and on which the tympan is brought down, is, by means of a handle or wheel, brought upon the metallic moving roller and under the scraper ; the pressure is applied with a lever, and continued from one end of the stone to the other ; when it has passed through the press, the lever is lifted, the moving table brought to its original place, and the printed sheet removed. The lithographic steam-press began to be generally used about 1867, and has quite revolutionized the lithographic trade.
The rollers for printing may be made of different lengths, from 6 to 24 inches long, and 3J to 5 inches in diameter. They are made of wood of the alder and lime tree, with wooden handles to project and hold by ; the roller is then covered with several complete turns of flannel, well stretched and fastened by sewing at the extremities near the handles ; the whole is then covered with calf-skin, sewed with great care, so as to fit tightly, and laced near the handles. For printing chalk, tints, and colours, skins of different prepara-tions are required. Hollow metallic rollers, covered with flannel and calf-skin, are in use on some parts of the Continent, where they are preferred to rollers made of wood.
The best varnishes for making the printing-ink are boiled from old linseed oil, of different degrees of strengththin, middle, strong, and very strong varnish ; for printing with gold-leaf, bronze, and dusting colours, the very strong varnish is required. For w-ritings, maps, and music, common calcined lamp-black is ground with the varnish ; some hard blue is added to improve the colour, and to make the ink dry in a short time ; for chalk ink, Paris black is used instead of the common lamp-black. For tinting and colour-printing, colourless or bleached varnish must he used, as otherwise the purity of the colours will suffer.
Printing. After the stones containing the writings or drawings in chalk and those used for tinting or colour-printing are etched, and the preparation has become dry, the stones may be put into the press and properly fixed. To prevent a stone containing drawings of any value from breaking, it should, if thin, be backed to another stone, or, what is better, to a slab of Aberdeen granite. This is done by a mixture of plaster of Paris and cold water, of the consistency of syrup, a pretty thick coating of which should be spread evenly and quickly on the slab ; the stone containing the drawing is placed into this layer, and moved in all directions until the plaster of Paris becomes quite hard, which will take place in a very short time. After the printing is accomplished, the stone can be quite easily removed from the slab, by using a chisel, and by giving some side strokes with a wooden hammer. The old dry plaster of Paris is now removed, and the slab is again fit for use.
Everything being ready, the gum is entirely washed away with a soft Turkey sponge and water ; the writing or drawing is then ob-literated by taking a clean sponge and oil of turpentine, to which maybe added, at pleasure, a few drops of sweet oil, after which the. stone must be cleaned with water. An entirely clean sponge (or for writings, a bit of soft canvas manufactured for the purpose) is now required for the printing. The stone is slightly wetted with this sponge ; the printing roller, charged already with the proper ink, is passed repeatedly over the whole stone, and the writing or draw-ing will begin to reappear ; the roller is again worked on the ink-slab, the stone wetted anew with the sponge, and again rolled over, until the writing or drawing appears in full strength. A sheet of damped paper (dry paper may he used for writings and drawings in line) is put on the stone, the tympan is let down, the scraper brought to its proper place, the pressure effected, and, by means of the handle, cross, or wheel, according to the style of press, the table with the stone is slowly and equally drawn through to nearly the end of the stone, for which purpose the press requires to be set properly beforehand. The printer now relaxes the pressure, the table with the stone runs to its original place, the tympan is put back, and the impression is carefully taken up from the stone. The stone is then again wetted as before, inked in anew, the paper placed upon the stone, and further impressions are effected. When the stone is to be kept after the required number of impressions has been struck off, it should always be inked up with preserving ink, which is made by melting lard, tallow, and wax, in equal propor-tions, with a quantity of printing-ink. When about to be used, this preserving-ink may be thinned with some oil of turpentine, thinly spread on a roller kept for this purpose ; it must then be properly turned on the slab ; the writing or drawing is washed out with oil of turpentine, the whole removed with a clean sponge, and the stone wetted and inked in with this preserving-ink. A few minutes afterwards, when the turpentine has evaporated, a thin solution of gum-arabic is spread over the stone, containing a little sugar-candy to prevent the cracking of the gum by change of atmosphere. The stone will keep any length of time; but the pre-serving-ink should be renewed at least every twelve months.
The printing of tint and colour stones is treated in the same way, only the rollers, varnishes, and colours are different from those used for ordinary black and chalk printing. The printing of this class of work requires great skill and taste. Many of the lithographic printers of London, Paris, Brussels, Munich, Berlin, Vienna, and Dresden are justly famed for their beautiful productions.
An engraved stone is printed by using a small wooden tapper or tampon, either round at the sides, flat below, with handle at top, or square, with the corners rounded off. This tampon is covered several times with a very coarse blanket, or coarse thick firm cloth, fastened at the sides ; the ink is then spread very thinly on the slab, the tapper is properly tapped into it, the gum is removed from the stone, and the drawing is removed with oil of turpentine ; the stone is wetted, the tampon is tapped over the whole drawing, the stone cleaned with a bit of wet canvas, and finally a printing roller is passed once or twice over the stone, which removes all impurities; a damped sheet of paper is then placed on the stone, and the impres-sion made as formerly explained.
Some printers print engraved outlines or drawings done with thin lines entirely with the roller, which is a great saving of time ; other printers again ink an engraving with a large shoe brush with long, stiff bristleswhich is rubbed on the ink-slab to give it the ink requiredby brushing over the drawing in all directions.
Paper.The proper selection of paper for lithographic printing when beauty of impression is a chief consideration, is of great importance. Hand-made and hand-sized papers are objectionable, the materials used in sizing being frequently inimical to perfect lithographic printing. Absorbent papers, such as India paper, plate-paper, half-sized plate-paper, and fine printing paper yield the best impressions ; common writing paper, hand-made writing, loan, or other hand-made English-sized papers should be used only when the work is for business or similar purposes. <- 1
Since the invention of photography, and its wide appli-cation to processes connected with art, artistic lithography, except in the way of colour printing, has been perhaps rather less in demand than formerly. Many of the finest British examples of lithographic art date from more than twenty to thirty years back, when artists such as J. D. Harding, Samuel Prout, Louis Haghe, Ghemar, William Simpson, and others were largelysome of them almost exclusivelyengaged in its practice. Harding, although practising as a water-colour painter, devoted much of his time to lithography. The dexterity and brilliancy of his execution give to his works in this style a peculiar charm, altogether wanting in the more laboured productions of the professional lithographic artist. Of this quality in Hard-ing's drawings on stone, Mr Buskin writes"His execu-tion, in its way, no one can at all equal. The best chalk drawing of Caíame and other foreign masters is quite childish and feeble in comparison." Samuel Prout, also a water-colour painter, produced many admirable works in lithography. Mr Buskin's testimony may again be quoted:" All his published lithographic sketches are of the greatest value, wholly unrivalled in power of composi-tion, and in love and feeling of architectural subject." " His lithographic work (Sketches in Flanders and Ger-many), which was, I believe, the first of the kind, still remains the most valuable of all, numerous and elaborate as its various successors have been. Their value is much increased by the circumstance of their being drawn by the artist's own hand upon the stone." Louis Haghe's work on the Architecture of the Middle Ages in Germany and the Netherlands, Roberts's Holy Land and Egypt (drawn on stone by Haghe), and Simpson's drawings of the Crimean war may also be cited as excellent examples of artistic lithography. Lithographic studies of heads and figures by Julien of Paris, and other foreign artists, were at one time largely employed as copies by drawing masters ; the new system of teaching introduced of late years has almost put an end to their use for this purpose, and they are now less frequently met with. Although lithography is increas-ingly employed for commercial and other purposes, artists of first-rate ability now seem, on the whole, to prefer other processes for the reproduction of their works. (G. RE.)
The above article was written by George Reid, R.S.A.