Stone-printing has the unique property, owned by no other process, that it is possible to print relief and intaglio simultaneously. This property makes possible so many combinations of the two processes that a book might be filled with their description. I assume, however, that the reader will have understood the entire science of the new art from what I have said, and that his own reflection will tell him what methods to use or to combine for each of his purposes. I limit myself, therefore, to a few leading methods, thus giving some fundamental idea of the manipulations.

I
PEN DESIGN COMBINED WITH ENGRAVING

This can be utilized in two ways:—

When the pen drawing is finished and etched, the stone may be coated with red gum covering and the needle used to draw-in the finest lines. The printing is the same as with pen work. The second way is to make the engraved or etched part of the design first, and after the stone has been rubbed-in with acid-proof ink, cleansed and dried, to draw-in the rest with the pen and chemical ink. As soon as the design is properly dried, it is etched a little and prepared, and otherwise handled like an ordinary pen drawing. Both ways carry the advantage that the pen can be used for those parts best done with the pen, and the engraving-tool for those parts best done with it. The latter is especially excellent for very fine and elegant script, such as title-pages, the finest strokes being made first with the needle and the broader ones with the pen.

II
INTAGLIO DESIGN WITH RELIEF TINT

This has been described thoroughly in our chapter on etched work.

III
INTAGLIO AND RELIEF WITH SEVERAL PLATES

As already shown, intaglio and relief can be printed on one stone. Therefore it is evident that the two methods can be utilized still better for several plates, for instance, printing on an etched design with one or more plates that are tinted in relief, or by printing over a crayon or pen design in relief a tone plate in aquatint in intaglio.

How to do this has been explained in the descriptions of relief and intaglio methods.

IV
TRANSFORMING RELIEF INTO INTAGLIO AND VICE VERSA

This is, so to speak, the test of a good lithographer, as it is the most difficult of all methods, and demands exact knowledge of all manipulations. I will try to explain it with a few examples.

EXAMPLE I
To etch a transfer into intaglio

Prepare a finely ground plate with phosphoric acid and gum, wash very well with water, and let it dry. Now transfer to it a design made with soft ink or crayon, or a fresh copper-plate impression. Let the stone rest for a few hours, that the fatty colors may take hold well. Coat it with clean gum water, and with a rag dipped into acid-proof ink try to rub about as much color on the design as appears to be required to make it withstand some etching. This etching is done with pure aquafortis which in addition has a little alum mixed with it. Etch only enough to eat away the uppermost parts of the prepared surface that have not been permeated with fat. Pour clean water over the whole stone and coat it with strong soap-water that is permitted to dry on it. Finally, clean away the soap with oil of turpentine. Ink-in with acid-proof color which will color the whole stone. Now as soon as it is wiped gently with a rag dipped in gum solution and weak phosphoric acid, the whole design will appear in white as if it had been made with preparing-ink. If the stone is inked now with acid-proof ink and treated exactly as instructed in the article on the use of preparing-ink, the design that was in relief originally will be found in intaglio.

This process is capable of great perfection and can produce true masterpieces especially if the stone is treated finally with the engraving tool.

EXAMPLE II
To etch into intaglio a design made with chemical fatty ink or crayon

Etch and prepare the clean stone with phosphoric acid and gum. Then put on the design with ink or crayon, and perform the succeeding etching and other manipulations exactly as in the preceding case.

EXAMPLE III
To etch into intaglio any design etched into relief

In the two examples given, the plate is etched with phosphoric acid before transfers or designs are made on it. As the weak etching with aquafortis and alum does not penetrate the places where there is fat, these retain their phosphorus-preparation, and thus are not so readily destroyed by the succeeding application of soap, whereas the etched parts immediately drink in the fat as soon as the soap touches them.

In stones designed in the ordinary way, where the design does not lie on the prepared surface, but has really penetrated well into the stone, the transforming is somewhat more difficult, but can always be done after practice by using the following means:— Wash the stone with water and then coat chemical ink or strong soap-water over it and let it dry. Then clean the stone with oil of turpentine and ink-in well with acid-proof color. Dip a linen rag into gum water and phosphoric acid and endeavor to wipe away the color from the relief design. After wiping to and fro quickly a few times, try with the finger if the design will not whiten, or if the wiping with the acid must be continued. Care must be taken not to injure the ground through too much pressure. When the design gets pretty white, ink the stone with firm acid-proof ink, and then treat as in the preceding cases.

In this way designs in relief that have not turned out as desired can be changed into intaglio, and then, by the use of successive coatings and etchings, as described before, improved by making gradations of tones. But it requires great skill, lacking which one may destroy his plates utterly.

EXAMPLE IV
To change an intaglio design into relief for easier printing

Many kinds of scripts and designs are easier to engrave with a needle than to do in relief with a pen; or one may have workmen who can use the engraving tool better than the pen, as the use of the latter requires more industry and skill than the use of the etching- or engraving-needle.

If one wishes to transform such a design into one in relief, because then it can be printed more quickly and easily and also will give more impressions, the following method will prove useful:—

Ink the stone with good acid-proof ink, and after a few hours etch it like a pen design till it is apparent that the design is showing up. Let it rest again a few hours after etching and become quite dry. Then coat with gum. Otherwise treat it for printing like an ordinary pen design.

Now I believe that I have described faithfully and as clearly as I can all the lithographic methods to which unceasing research and endless experimentation have led me. In the following Appendix I merely make a few useful remarks, which do not pertain exclusively to lithography, yet are intimately connected with it and surely will not be unwelcome to art lovers.