After a few minutes the stone is withdrawn from the press, the paper is lifted off and the stone permitted to dry for a minute. It is better if one can wait longer. Then put it into the etching-trough, and pour over it, quickly and only once, a clean but weak solution of one hundred parts of water to one part of aquafortis. It is necessary to be skillful enough to cover the whole surface with one application. Then the stone is washed by pouring pure water over it, and, if time permits, set aside to dry. If time is limited, the gum solution to prepare the stone can be put on at once. Now the transfer is on the stone, properly etched and prepared. To make clean impressions, however, the printing-color must first be rubbed on, then the stone must be inked-in with acid-proof color and after that undergo another etching, a trifle stronger.

To rub on the printing-color, rub a little acid-proof color into a piece of clean linen or cotton, so that it is well permeated but not thickly covered. Rub this rag gently to and fro over the transfer while the gum is still on it, till every part of the design is nicely inked. This rubbing-in of color is an important part of many of the processes that will be described later.

Now clean the stone well with water, ink-in with acid-proof ink, and etch it again as has been described several times. Then it is ready for printing. The last etching is not necessary if only a few impressions are desired.

Transfer is applicable not only for pen designs but also for crayon. The crayon used for the purpose should be softened a little with tallow, or, if the harder crayon is used, the stone should be warmed when making the transfer. But it must not be inked-in or have color rubbed on, until it is quite cold again. For crayon transfer the paper used generally is fine drawing-paper. It must be wetted with somewhat stronger aquafortis that it may release the crayon more readily. The rest of the process is the same.

Besides these two methods, the transfer process can be used for all products of the book-printer's art, type as well as wood-cut. A freshly printed sheet can be transferred directly to a stone, especially if the printer has used our before-mentioned acid-proof ink instead of his ordinary printer's ink. To get a perfectly clear transfer it is necessary merely to see that the printer does not use too much overlay, which would stamp the type too deeply into the paper; and that before trying to transfer the printed sheet to the stone it is subjected to gentle pressure in the press to free it from all inequalities. To do this without at the same time risking any loss of ink which might subsequently weaken the transfer, the sheet is well wetted, laid on a clean, wet stone that has been prepared so that it will not have any inclination to take color, and subjected to a very slight pressure, the press being used with almost no tension. This makes the printed sheet beautifully even. Then if it is transferred to a stone properly prepared as described before, the transfer will be perfect.

Even old book pages can be freshened up and transferred. I have spoken already of those that are on unsized paper. With prints on sized paper the method is as follows:—

Make a paint-like mixture of fine chalk and starch paste. Thin it down with water and paint the sheet. Dip a bit of linen rag into a thin color made of thin varnish and tallow tinted with vermilion. Touch-up the wet paper with the rag till every bit of type has taken red color. Pour clean water over it and touch-up the paper everywhere with a ball of fine cloth stuffed with horsehair. This will remove all surplus color. Continue this till the type matter is only faintly red. Then the paper must be washed very thoroughly with many pourings of water and laid between waste paper sheets to remove all surplus moisture. The transfer and so on must be done then as in the other cases.

Good transfers can be made also from a copper-plate engraving if the copper-plate impression is made with our acid-proof ink. The ordinary copper-plate ink is not so good. It will be self-evident that designs on stone can be transferred and reproduced the same way.

The tracing process has the property in common with the transfer process that it transmits only a small amount of fattiness to the stone and requires subsequent rubbing-in of color to give it strength.

Coat a piece of thin and clean vellum paper with tallow and lampblack and wipe it off again as neatly as possible, so that there remains only a thin film, which will not smut the stone when laid face down, unless pressure is exerted. Now draw on this with a clean English lead pencil that contains no sand, or with a composition of lead, zinc, and bismuth, and the pressure will force the design on the stone and transfer its fat, which then penetrates the stone and will give impressions. In preparing a stone thus made, greater care in etching is necessary than even in the transfer process. Very weak aquafortis solution must be used.