Chapter 12

The ink is made of fine bone dust, vegetable or other form of carbon, which has been carefully cleansed from foreign matter and ground to the necessary fineness in combination with burned linseed oil. Its strength and consistency should be varied according to the plate which is in hand, and the color also may be varied to suit the character of the plate by the addition of pigments.

The paper used in plate printing may be one of several kinds, but the usual variety is a fine white paper free from spots and imperfections which might mar the appearance of the finished print. This paper is made either by hand or machinery of selected bleached cotton rags, and has a soft, spongy surface which yields readily under the pressure of the plate. Before it can be used the paper is moistened and allowed to stand for from one to twelve hours, or even longer, until it becomes evenly and thoroughly dampened,--but not wet,--so that it will more readily force itself into the lines of the plate and take therefrom and hold the ink.

Before printing a photogravure, mezzotint, or other engraved plate the printer must first carefully examine it to see that it has no scratches, and that no dried ink remains in the lines from the last printing, and, in fact, that there are none of the many possible impedimenta which might prevent the production of a perfect print. The plate being in proper condition, it is then thoroughly cleansed with turpentine or benzine, all traces of which must be carefully wiped from the surface before the ink is applied. The plate is then laid on the heated iron box or "stove" until it has become thoroughly warmed. The surface of the plate is covered with ink, put on by means of an ink-roller, or perhaps the old-fashioned dauber, and the ink is thoroughly worked into the lines or depressions in the plate. After this the ink on the flat surface of the plate is entirely removed by wiping with rags. The printer's hand, which has become more or less covered with ink from the rags, is then passed over a piece of chalk, or gilder's white, and lightly rubbed over the surface of the plate, to remove the last vestige of the ink, leaving a highly polished flat surface with the incised lines or depressions filled with ink to the level of the surface.

The plate is then ready for printing and is placed on the bed of the press, a sheet of dampened paper laid upon it, and both are then run between the rollers of the press. As the top roller is encased in soft blankets, the soft, dampened paper is forced into the ink-filled lines of the plate, and when the paper is removed the ink clings to it and shows an exact impression of the engraving. This entire process must be repeated for each print made from an intaglio plate.

While the printing of a steel engraving or photogravure is a more or less mechanical operation, the printing of an etching--and "dry points" may be included--is oftentimes as much of an art as the actual etching of the plate. The two styles of printing may be compared to two kinds of fishing,--that of fishing for flounders with a drop line, from a flat-bottomed boat at low tide when one must just sit tight until one has a bite, and then haul in the fish, bait up, drop the line and wait again, as against that of angling for trout on an early spring day, dropping the fly in a likely spot without success at the first cast, persevering until rewarded by a rise and then by the sport of playing the fish, giving him line and reeling him in as about he circles and finally is landed. A good one, perchance, but the sport was in landing him. So it is with printing an etching. There is the opportunity to play with, and work hard over, a plate. Perhaps the etcher has not, for reasons only known to himself, put in the plate all that can be shown in the print by ordinary printing. The printer actually has to interpret in his printing the etcher's meaning, for the which, as a rule, he gets "more kicks than ha'pence," and in the end wishes he had stuck to plain plate printing as far as the profit is concerned.

In the process of printing an etching, the printer first covers the plate with ink and then wipes it with the rags, and, if necessary, with the hand. It depends entirely upon the etched work of the plate as to how it must be wiped, and it rests with the printer to prepare a proof which is satisfactory to the etcher. The plate is wiped "closely" where the high lights are required or a tint (a thin coating of ink) left over certain portions where it needs to be darker. After this the plate is "retroussed," which is accomplished by passing a very soft piece of fine muslin, or a "badger blender,"--a soft brush used by artists,--delicately over the work in the plate and drawing the ink up and over the edges of the lines. This softens and broadens the lines and gives a very rich effect, and, if continued sufficiently, fills the spaces between the lines and produces an almost black effect. All this work is varied according to the wishes of the etcher. A plate that left the etcher's hand a mere skeleton may be made to produce a print which is a thing of life. The possibilities of an etching in the hands of a skilful printer are almost limitless; the effects can vary with every impression, each showing a new picture. His processes are as interesting as those of the etcher himself, and it is within his capabilities to transform an etching from a broad daylight effect into a moonlight scene, including the moon, by judiciously, or injudiciously, inking and wiping the plate.

A "dry point" plate is produced by drawing on a copper plate with a steel or diamond point, and without biting by acid. The lines are cut into the copper and a burr thrown up which holds the ink in printing, and produces a soft, velvety line. The method of printing such a plate is similar to that of an etching, but the possibilities are not as great in the printing, as they rest to a greater extent upon the work of the artist. A great depth of color, producing wonderfully rich effects, can be obtained and the finer lines can be made much more delicate than by any other method.

The printing of intaglio plates in color flourished for a short period in the latter portion of the eighteenth century, and the best prints of that time now in existence are of rare beauty and bring enormous prices. The process, now almost a memory, is a costly one, and this prevents its use in book illustration excepting for volumes which command a very high price. This kind of printing requires the plate to be actually painted by hand with inks of such colors as the picture may require, and the painting has to be repeated for every impression that is taken. The colors are put on with a "dole,"--a small piece of muslin turned to a point,--and great care must be taken that they do not overlap, or run into, each other. As each color is placed, the plate is wiped clean with rags as already described, and when all the colors have been properly placed, the plate is pulled through the press in the same manner as in ordinary printing.

The successful printer of color plates must be a rare artist or else work under the direction of an artist. Little of this work is now done except in Paris and Vienna, and the limited number of color plates of this kind used for book illustration in this country does not warrant the time and expense necessary to train printers capable of doing the work. Even English plates are usually sent to Paris to be printed.

It is difficult to describe the work of what is termed artistic printing. Every plate is a subject to be treated by itself, and no hard and fast rule can be applied. It is really a matter of artistic feeling, and to revert to the simile of the angler, one cannot explain how a trout should be played, but can only say that it depends on the fish, the water, and the circumstances. A fisherman can _show_ you, if you are on the spot, and so can the printer.

THE GELATINE PROCESS

By Emil Jacobi.

Of the many photo-mechanical processes which have come into existence in recent years, the photo-gelatine, next to the half-tone process, has shown the greatest adaptability for practical use in art and commerce.

Whatever the name may be,--Collotype, Artotype, Albertype, Phototype, or Carbon-gravure,--the principle is the same; an impression is made in printer's ink from a photo-chemically produced design on a gelatine surface, either on the hand-press or on a power cylinder press similar to that used in lithographic printing.

There is hardly any process which is more capable of producing fine works of art. It is the only true method for reproducing, in the full sense of the word, an etching, engraving, a drawing in pen and ink, an aquarelle, a painting, or objects from nature. The depth and richness of tone of an engraving, the delicate tints of an aquarelle or india-ink sketch, and the sharpness of the lines of an etching or pen sketch can be reproduced with such fidelity that it is often impossible to distinguish the copy from the original, and this is achieved the more easily as the printing can be done in any color and on any material, be it paper, parchment, leather, or textile goods.

Another great advantage of a gelatine print is its inalterability and durability, no chemicals being employed in transferring the picture to the paper. The picture itself being formed by solid pigments, such as are used in printer's ink or painter's colors, there is no possibility of its fading or changing color, which cannot be said even of platino prints, at present considered the most lasting of all photo-chemical processes.

Like all new inventions, the photo-gelatine process, in its early stages, had to undergo severe trials, and for some years almost disappeared from public view, after many failures precipitated through unscrupulous promoters and inefficient persons who claimed impossibilities for the new process. It took years of patience and perseverance to regain the lost ground and overcome the opposition of those who had suffered by the failure of this process to produce the promised results; but at present it is, in Europe, one of the methods in most general use for illustrating, and in this country it is making steady progress and rapidly finding favor.

The process, simple as it may seem to the casual observer, requires, more than any other photo-mechanical process, skilled hands in its different manipulations to keep it up to the standard of perfection. The following short description will give the uninitiated sufficient enlightenment to think and speak intelligently about it.

The foundation or starting point, as of all the other photo-mechanical processes, is a photographic negative; that is, a picture on glass or some other transparent substance, in which the light parts of the picture appear dark, and the dark parts light in transparency, graduated according to the different shades of tone in the original. The next and most prominent feature is the printing plate. A perfectly even glass, copper, or zinc plate is covered on the surface with a solution of fine gelatine and bichromate of potassium, and dried. This printing plate is then placed under a negative and exposed to the light. The action of the light on the bichromated gelatine forms the basis of this process. In proportion to the graduated density of the negative, the light acts more or less on the bichromated gelatine, rendering the latter, in proportion, insoluble and hardening it. After sufficient exposure the plate is washed out in water to eliminate the bichromate not acted upon by the light, and is then actually ready for the press.

If the printing is to be done on a hand press, a lithographic leather roller is charged with printer's ink, and the plate, which has been fastened on a suitable bed-plate in the press, is rolled up while it is still moist. Those parts of the plate which were acted upon by the light and hardened, repel the water and take up the ink, and thus all the graduating tones, up to the high lights or white parts, which have not been affected by the light, will take the ink proportionately. The white parts of the picture, where the light did not act upon the gelatine during the exposure under the negative, retain the natural property of gelatine to absorb water, and consequently repel the ink altogether.

From the foregoing it will be easy to understand that a certain degree of moisture in the plate is necessary to get a correct impression. After the leather roller, a composition roller, such as is used in typographical processes, is employed to make the ink smooth and give the fine details not obtainable from the rough surface of a leather roller. A sheet of paper is then placed upon the plate and by pressure the ink is transferred from the plate to the paper.

The printing, in former years, could only be done on hand presses; but with the introduction of improved power presses especially adapted to it the process itself has been so perfected that the finest work can be executed on them, at the same time insuring greater evenness and increased quantity of production, and also admitting the use of larger plates than would be possible on a hand press.

The prevailing impression, whenever machinery is employed to supersede hand-work, is that the production is increased to such an extent as to reduce the cost to a minimum, but in the gelatine printing process, even with the aid of power presses, the rapidity of printing is far behind the possibilities of the lithographic or typographical printing press, and the process, therefore, is only applicable to works of art, and the better grade of illustrations in literary and commercial publications.

The lesser rapidity of production and the greater cost is balanced by the quality, where this item comes into consideration; and where only small editions are required, even the cost compares favorably with other methods, as the initial cost of preparing the printing plate is small compared with the cost of photogravure or the better class of half-tone plate. It is only in cases of large editions of many thousands that the advantage of rapid printing reduces the cost of the initial expense. But fine art publications and illustrations will never be used in very large quantities, and, therefore, there is a large field for the photo-gelatine process in this country, where it is as yet so little used. In France, Germany, and Austria there are dozens of establishments which employ ten or more power presses for photo-gelatine work, while here only within the last few years has the process been sufficiently appreciated to warrant the introduction of a few steam presses; and these have to be imported from abroad at a high rate of duty, as the present demand for the presses does not make it advisable for our domestic press builders to invest in their construction, especially after an isolated attempt in that line, misguided by inexperienced and unpractical men, which turned out to be a total failure.

Notwithstanding all these difficulties and obstacles, it is a fact that the photo-gelatine process has gained ground sufficiently to indicate a prosperous future, as its products are becoming more widely known and appreciated.

LITHOGRAPHY

By Charles Wilhelms.

As an embellishment to the modern book, chromo-lithographed illustrations are quite popular and in some cases absolutely necessary, being not only attractive, but conveying an accurate idea of the color as well as the form of the object illustrated. Although the illustration is nothing more than a colored print, it may be a revelation to some when they learn of the numerous details incidental to its production.

It may not be generally known, and yet of sufficient interest to the reader to state that the art of lithography, or surface printing, was invented accidentally. The inventor, Aloys Senefelder, had been engaged for years endeavoring to find some process for etching copper plates as a substitute for typographic printing plates; and the piece of stone (of a kind now known as Solenhofen lithographic stone), which eventually led him to the discovery of lithography had been used by him as a slab upon which he had been accustomed to grind his printing ink. The materials which he used for his acid-resisting mixture while etching his copper plates were beeswax, soap, and lampblack, and in selecting these materials he accidentally invented the basis for all crayons or lithographic "tusche" or inks, now used so extensively for drawing on stone. It seems that Senefelder finally became thoroughly disheartened about his etched copper plates, mainly owing to the great expense and labor connected with their production, and was about to discontinue his efforts when the idea occurred to him to experiment with the stone which he had used as an ink slab for so many months, treating it in the same manner as the copper plates.

He knew that the calcareous stone was easily affected by acid and that he could protect its surface against it by a layer of wax. After polishing the surface of the stone and coating it with a slight layer of wax, he made his drawing with a pointed tool, laying bare the surface of the stone where he desired the engraving. Then applying the acid and removing the remaining wax, he filled the etched lines with printing ink, cleaned the surface of the stone with water, and was enabled to obtain an impression on paper from it. This manner of treating a stone has been employed by vignette engravers for many years, but of late has become obsolete. The result gave encouragement to Senefelder and induced him to renew his experiments, when he was accidentally led a step farther in the direction of surface or chemical printing.

Senefelder had just ground and polished a stone, when his mother entered the room and asked him to take a memorandum of some clothes which she was about to send away to be laundered. Having neither paper nor ink at hand, he hastily wrote the items with a pen, dipped in his acid-resisting mixture, upon the stone which had just been polished. When he afterwards started to wipe the writing from the stone, it occurred to him that it might be possible to reverse his process by etching the surface of the stone, leaving the writing or drawing in relief, which could be printed from in the same manner as from type. He was fairly successful in this, and after many disappointments and much hardship, he eventually succeeded in interesting a capitalist, with whose assistance he was enabled to establish his new relief stone process on a commercial basis.

The process, however, was at best only an imperfect one, and it seems strange that the final discovery of surface or lithographic printing should have been so long delayed, when Senefelder was in reality so near it, when he first poured the acid over the stone containing his laundry memorandum. If he had instantly washed off the acid and cleaned the surface of the stone with water, he might have proceeded to print thousands of impressions by simply keeping the surface of the stone moist while passing the ink roller or dabber over it, then drying and taking an impression, and repeating this operation indefinitely. It is not surprising, therefore, that a man of such persistence and capability as Senefelder should eventually discover the best method for drawing and printing from stone; for it is a fact that, since he perfected his invention, more than a hundred years ago, it has been hardly possible to improve on his methods, so completely did he cover the entire field of manipulation in this direction. Continuing his experiments, Senefelder finally found that the calcareous stone absorbed and held grease, and that it just as readily absorbed water, where the surface was exposed and clean; that any design drawn or transferred with a greasy crayon or ink upon a cleanly polished stone would be firmly held, after being slightly etched; and that after such a stone had been moistened, it could be inked with rollers, the ink adhering only to the greasy matter constituting the design (although it did not stand out in the relief) and that the ink rollers would not smut the stone, the ink being repelled by the water or moisture covering its surface. Upon this principle of chemical affinity, the adherence of greasy substances to each other and the mutual antipathy of grease and water, the art of lithographic printing is based.

The methods or processes now employed in reproducing oil-paintings, colored photographs, or water-colors by lithography are numerous, and require great skill and experience, not only on the part of the lithographic artist, but also on the part of the printer. Photography has of late years been used to a great extent in creating the basis of the color plates, to be afterwards perfected by the manipulation of the experienced chromo-lithographer.

To insure a satisfactory result the first essential is, of course, a good original, which can be made in water-color, oil, or pastel. The number of printings to be employed should be predetermined and a color scale adopted. The lithographer must carefully analyze the original painting, making his calculations as to the best way of obtaining the desired color effects by a judicious selection and use of his colors, and the superimposing of one printing over the other, so as to obtain true color values. It must be remembered that, while the average painter has an unlimited variety of pigments at his disposal, the lithographer is in this respect very much at a disadvantage, not usually having more than from six to fourteen colors with which to produce a facsimile of the original.

The first step is the making of the so-called key-plate. A piece of gelatine is laid on the original, which is, let us say by way of illustration, a water-color to be reproduced in ten printings, and a careful tracing of the original is made by scratching, with an engraving needle, the outline of each wash or touch of color composing the picture. This being completed, the lithographic ink (tusche) or transfer ink is carefully rubbed into the tracing, which is laid face down on a polished lithographic stone, slightly moistened, and passed through a hand press; thereby transferring the ink from the engraved lines to the polished surface of the stone. The design on the stone is then rolled in with black printing ink and etched, thus enabling the lithographer to take the necessary ten impressions of the key-plate. These, in their turn, are again transferred to as many lithographic stones. This is accomplished by dusting the impressions with a red powder, which adheres only to the design printed on the sheet. The powdered outline design is then transferred to the surface of the stone by passing both through a hand press. The key has been previously provided with register marks (a short horizontal line intersected by a vertical one) at top, bottom, and both sides. These are of the utmost importance to the prover, and finally to the transferrer, who prepares the work for the press, as without them it would be impossible to register one color over the other in its proper place. At any stage of the process, the register marks of all ten colors, which have been made in succession on a single sheet of paper, should coincide precisely and appear as a single mark in the form of a small cross.