The stone, which must be very clean and free from all fat, is grained, coated with soap-water, cleaned with oil of turpentine, and dried. Then a hard chemical ink, which may contain a little more soap than usual, or the ink described for brush work, is dissolved in pure rain water and used on the stone with a brush just as it would be used on paper. When the design is finished and very well dried, the entire surface of the stone is rubbed gently with a fine cloth, in order to perforate the color with tiny holes everywhere. As it will perforate more readily in the parts where the ink has been laid on thinly, the succeeding aquafortis will eat through there more easily, and thus the etching will correspond nicely with the tones of the design. It is necessary, however, to know the strength of the acid and the resisting power of the ink very accurately. It is well to experiment and write down the best proportions. In any case, the etching fluid must not be too strong and the etching must not be done by pouring or brushing, but in the copper etcher's manner, by framing the stone with wax so that the fluid will lie on the stone. As soon as the resulting bubbles reach the magnitude of a pin's head, the fluid is poured off instantly and then poured on again till the bubbles reappear. How long this must be continued depends on the strength of the ink. It is understood, of course, that the etched stone must then be coated with gum. VI THE SPATTER METHOD This speedy and easily executed style surely will come into wide use soon. It is done as follows:-- The outlines of a design are laid on a stone prepared for pen work, by tracing. Then they are traced again, say four times, on sheets of paper. On each sheet everything that falls into the category of one of the four chief tones is cut out with a sharp penknife so that the four sheets are like the stencils of card painters. Now the chief lines of the design are made on the stone with chemical ink, using either brush or pen. Lay one of the stencils on it exactly, weight it that it may not move, and perform the operation of spattering. This is done by dipping a small brush, such as a clean toothbrush, into chemical ink and scraping it with a knife so that the ink is spattered over the stone. Care must be exercised not to have too much ink in the brush, for fear of blots or over-large spattering. After practice it will be possible to produce such fine and uniform dots as cannot possibly be produced by the pen. After the desired grade of shading has been achieved, the stone is permitted to dry. Then the second stencil is laid on and the operation repeated till all have been used. If enough stencils are made, the whole design can be made by spattering. It is not necessary, however, to make many, as the design has to be finished up by hand afterward anyway.