Purple Tint for Marking Linen.

Practical Magazine 14, 1876

(Chemistry applied to the Arts, Manufactures, &c.
Dyeing, Calico Printing, Bleaching, Tanning, and Allied Subjects.)

A suitable preparation for this purpose is as follows: – Let 5 grammes (1.7 oz.) of sesquicarbonate of ammonium be neutralized in a porcelain mortar with nitric acid, and the perfectly neutral solution have 3 or 4 grammes (.1 or .14 oz.) of carmine ground into it. As a mordant for the linen, use a mixture of equal parts of acetate of argillaceous earth and nitrate of tin. Linen or cotton thus treated and marked with the above preparation will, when perfectly dried, show a purple tint.

- Industrie-Blätter, Dec. 30th, 1875