The staining of leather may either be done free-hand, or else by the filling in of set designs, marked out previously by tooling or some other method; or, as will be discussed later, by the use of stencils. In any case success chiefly depends upon the condition of the surface that is to receive the dye. The surface of the leather should be dampened, thoroughly and evenly, so that the dye will adhere, and even penetrate a little; but it must not be so wet that the colors will run.
To get this exactly right requires considerable practice. As a rule, the leather is, first, carefully and evenly soaked in water or, if it is at all greasy, in water with a little ammonia in it. When this has been thoroughly done, the leather is taken out and dried off, first on one side and then on the other, with pieces of cloth and then later with blotting paper. After this it is exposed to the air for a little time until the exact point of dryness has been reached.
The color solution should be applied with a camel’s hair brush or a small, soft pad of cotton, and any excess of liquid wiped off, or soaked up with blotting paper, and the color rubbed in with the fingers or pad, as soon as possible.
Acid Dyes for Leather.—As above mentioned, certain shades are hard to obtain without the use of Acid colors. This is particularly true in the case of blue. For the lighter and brighter shades it is necessary to use one of the Acid blues such as Cyanole FF. (Cassella), or Patent Blue (Metz). These are applied in exactly the same way as the Basic colors. Some of the Acid reds, too, will be found valuable for certain shades of scarlet, etc., that can hardly be reached with Safranine. Among the best of the fast Acid colors for leather may be mentioned:
Red.—Fast Scarlet, BXG, Badische; Biebrich Acid Red, 2B, Kalle, and Fast Acid Red, M, Metz.
Yellow.—Tartrazine, Badische; Wool Yellow, 1A, Kalle, and Fast Acid Yellow, 3G, Metz.
Blue.—Wool Fast Blue, BL, Badische; Nerocyannic Blue, B, Kalle, and Fast Acid Blue, BB, Metz.
When using these Acid dyes side by side with the Basic colors, it will be noticed that the latter, as a rule, are far more powerful, and color the leather much more rapidly than the Acid dyes. Accordingly forstaining leather the Basic dyes are the most satisfactory. On the other hand indyeing leather, where the dye-liquor is allowed to act longer on the goods, the Acid colors are more valuable, not only because they are fast to light, but also because they will penetrate more deeply and more evenly.
Finishing Leather.—After coloring the leather it is necessary to finish it carefully, to get a smooth surface and to protect it from injury by rubbing or moisture. Some workers simply let the leather dry and then rub down the surface (without using any wax or oil) with the finger or the palm of the hands. Usually the grain or hair side of the leather is rubbed down with a little wax, the white or yellow wax, used largely as a finishing polish for tan shoes, being frequently employed for this purpose. It can be readily obtained from almost any good shoe store or, if desired, can be made by mixing together equal quantities of beeswax and carnauba wax in a molten condition, and thinning the mixture with a little turpentine.
A recipe used with success by many leather workers calls for a mixture of beeswax, turpentine, and neatsfoot oil. The wax is carefully melted, mixed with a small amount of turpentine, and then enough oil is stirred in to make it soft. When used upon embossed or figured leather this wax is never applied directly, but is placed inside a little bag of soft muslin, and rubbed on and into the leather with a circular motion—the palm of the hand being often used to finish the waxed surface.