Blue.—Prussian blue ground up with solution (nitromuriate) of tin; thickened, &c.
Yellow.—Nitrate of lead dissolved in solution of tartaric acid, thickened, tenderly dried, passed through the bichromate vat or padding machine, washed and dried.
This yellow is pretty fast; though topical, it can hardly, therefore, be called a fancy colour.
When purple is to be inserted instead of the above blue, extract of logwood with tin is used in the place of the Prussian blue. Tartaric acid is a useful addition to tin in brightening fancy colours.
Chocolate.—A good topical chocolate is made by digesting logwood with liquid acetate of alumina, adding a little cream of tartar to the infusion; thickening, applying by the cylinder, drying, washing, then passing through solution of bichromate of potash, which serves to darken and fix the colour.
I shall conclude my account of the printing of cotton goods with some miscellaneous formulæ, which were given me by skilful calico-printers in Lancashire.
Prussian blue is prepared for topical printing by grinding it in a handmill, like that for grinding pepper or coffee, and triturating the powder with solution of muriate of tin.
Green.—The deoxidized indigo vat liquor is mixed with a little pearlash, and thickened with gum. This is applied by the cylinder or block to goods previously padded with nitrate of lead; the goods, after being dried, are passed through milky lime-water, rinsed, and then winced or padded through the bichromate of potash bath.
Another green.—Nitrate of lead, prussiate of potash, and tartaric acid, dissolved, and mixed with a little sulphate, nitrate, and muriate of iron; this mixture is either thickened for cylinder printing, or used in its liquid state in the padding trough. The goods subjected to one of these two processes are dried, padded in weak solution of carbonate of potash, which serves to precipitate the oxide of lead from the nitrate; they are finally padded with bichromate of potash, which induces a yellow upon the blue, constituting a green colour of any desired tint, according to the proportion of the materials.
Chocolate and black, with white discharge; a fast colour.—The cloth is padded with acetate of alumina, and dried in the hot flue; it is then passed through a two-colour machine, the one cylinder of which prints-on lime-juice discharge, thickened with gum senegal; the other a black topical dye (made with logwood extract and iron liquor). The cloths are now hung up to be aired during a week, after which they are dunged, and dyed up with madder, fustic, and quercitron bark, heated with steam in the bath.