(e)Wood.—Batiked wood can be stained by soaking it in, or by brushing it with, a solution of an acid color, acidified with a little acetic acid. These dyes are more soluble than most of the other classes, and hence soak into and penetrate the fibres better. They may bleed, however, if exposed to warm water.
The Basic colors or even the Salt colors can be used, but, while they are apt to adhere more firmly, they do not soak in as well.
The wax is either used for polishing, or is removed by benzine.
(f)Baskets.—Basketry can be decorated by Batik, although it is but rarely done. The baskets would be dyed with Basic colors and acetic acid, excepting where yellows and reds were needed, fast to light, in which case the Acid colors would be used.
(g)Bone.—Very pretty effects can be produced with Batik upon polished surface of bone or ivory. These are dyed carefully with Acid colors in a bath containing acetic acid.
This process is a combination of dyeing and etching, for the acid attacks the exposed surfaces, removing the polish and opening the way for the action of the dyestuff later.
Batik Used for Etching.—The talents of Batik are numerous, for the usefulness of the Batik tjanting and brush are not confined to the dyer, but can be readily availed of by any metal or wood worker who happens to be a skilled draughtsman as well. Wax is a good resist, not only against dyes and the weak chemicals used in connection with them, but also against many of the most powerful reagents known to the chemist, such as sulphuric acid, for instance, or strong caustic alkali.
Accordingly, if a piece of smooth wood is carefully batiked and then, instead of being painted with dyestuff in solution, it has some strong sulphuric acid, or a concentrated solution of caustic potash poured and spread upon it, in a few minutes, after the reagent is washed off and the wax removed with gasoline or otherwise, the exposed surfaces of the wood will be found softened and corroded, so that on scrubbing with a stiff brush, they can be readily rubbed away, and the waxed portions will stand out in relief.
Metal work, like copper or brass plates and dishes, can be etched readily in the same way, the pattern of the relief being drawn in wax, and the metal exposed for a greater or less time to the action of dilute nitric acid.
Without going further into details it is hoped that enough has been stated here to impress on the student the possibilities of this beautiful process in a large number of different directions.