Paper and Printing Recipes / A Handy Volume of Practical Recipes, Concerning the Every-Day Business of Stationers, Printers, Binders, and the Kindred Trades

by John Sawtelle Ford

Coloring Metals.

Metals may be rapidly colored by covering their surfaces with a thin layer of sulphuric acid. According to the thickness of the layer and the durability of its action, there may be obtained tints of gold, copper, carmine, chestnut-brown, clear and aniline blue and reddish-white. These tints are all brilliant, and if care be taken to scour the metallic objects before treating them with the acid, the color will suffer nothing from the polishing.