So I close my description of the Relief method; and I hope that I have made it all so clear that good results will come to all who follow my directions.
[CHAPTER II]
INTAGLIO METHOD
This differs from the other in that the fat, which is to attract the printing-color, is under the surface of the stone, the design having been either engraved-in or etched, and then filled with fat.
Like the preceding method, it has several branches. The best are these:—
I
THE LINE ENGRAVED STYLE
This is one of the most useful branches of lithography, and if the artist has attained enough skill and the printer knows his trade, it approaches very near to the handsomest copper plates, and at the same time is about three times easier and quicker than work on copper. It is splendidly adapted for writings and charts.
Choose a hard, uniform stone of the best kind. Grind it as finely as possible. Etch with aquafortis and prepare with gum. This, at least, was my early method, and it has remained in use in all printeries. Later, however, I discovered that it is almost better to coat the stone with gum without previous etching, because it can be more easily worked then. Only in that case it must be perfectly clean and contain no concealed fattiness. Immediately after the stone has been coated with gum (not some hours later, as many do) the gum must be removed with water, that it may not penetrate too deeply and thus cause a condition which will prevent the finest lines from taking on color subsequently.
Then coat the plate with a tint made of gum solution and lampblack or red chalk. Use a soft brush to make the coating very thin and uniform. It has the double purpose, first, of giving the stone a color so that the engraver can see his work, and of covering the prepared surface of the stone with a protective coat that later will admit the fatty printing-color only where it has been pierced by the engraving-tool. It is evident that this latter property is increased according to the amount of gum in it, yet only little gum must be used in it, the permissible amount being only just enough to insure that the coating shall not be easily wiped away during the work of engraving.
The stone must be absolutely dry before any work is done on it. Then the design is traced on it, or drafted directly on it with lead. Transfer by printing from paper is not advisable, because the resulting fattiness of the design makes the graver slip.