A brush and sponge can be used for applying the the dye liquor, but to prevent the coloration being uneven, patchy or streaky, the fluid should be quickly and evenly applied all over the surface to be dyed; the operation should be rapidly performed, and sufficient dye liquor be contained in the brush or sponge to flow over the whole of the surface at once. This is necessary, because wherever the dye just touches the wood it sinks into the fiber at once, and the tone of color obtained depends on the strength of the fluid ; that is, a spongeful of the fluid produces a deeper coloration than that which is obtained when half the liquor has been absorbed out of the sponge; therefore, be rapid in the application, and keep up a plentiful supply of the dye to the surface, until it is all flooded evenly with the dye.

Then let the wood remain in a warm room to dry; owing to the thinness of fretwork it is liable to warp and curve up if too much liquid be applied at once. Therefore it is best to have the dye liquor of sufficient strength to strike the tone at once by a single application, but when graduations of tone are desired, the strength of the dye liquor can be weak at first, and successive applications of stronger liquor made, but each one should be nearly but not quite dry before applying the next.

Any attempt to keep the wood flat by laying weights on it while the surface is wet with the dye will only spoil the coloration. If the wood does curve up, it is best made flat again by first allowing the dyed surface to dry and then wetting the wood on one or both sides and laying if between two boards that are weighted down; the dye having soaked into the fiber and become combined therewith will not be so liable to be rubbed off when wetted subsequently.

Another way to straighten the wood is to hold it over the spout of a kettle from which steam is escaping, and then lay it flat between boards. If the wood is to be colored on both sides, and be stained throughout its thickness, it is best to steep the wood in the dye liquor for three to five minutes, at a suitable temperature, remembering that the hotter the temperature of the dye liquor the deeper the stain produced.

After coloring the wood, its surface should be smoothed by lightly sandpapering. If the fiber is not raised by the hot liquid, or if only slightly raised, it maybe smoothed by rubbing it with a piece of stiff felt. To fix the dye in the fiber so that it shall not be rubbed off if the wood becomes wetted or damped, a wax polish can be used, or a solution of casein may be laid on the surface with a sponge or brush and allowed to dry. The casein solution is made by dissolving dry casein in a saturated solution of borax until the mixture results in a fluid of the consistency of gum mucilage.

Dye solution can be used in exactly the same way as above described for dyeing and coloring leathers, provided the leather has not been previously colored. In some few cases it will be found necessary to employ a "leveller"; that is, a fluid applied to the wood before the application of the dye liquid, so that the dye will spread on the fibre uniformly, and produce an even coloration. Such levellers are usually sulphate of soda, acetic acid, sulphuric acid diluted, common salt, acetate of soda, etc.