Etching Fluid For Zinc.
Relief Etching Of Zinc.
Another compound for the drawing is made of blue vitriol, 2 parts; copper chloride, 3 parts; water, 64 parts; pure hydrochloric acid, 1.1 specific weight. After the drawing is made, lay the plate in dilute nitric acid (1 in 8). {324}
Etching Fluid For Aluminum.
Etching Fluid For Tin Or Pewter.
Etching Fluids For Silver.
II.—Nitric acid (specific weight, 1.185), 172 parts; water, 320 parts; potassium bichromate, 30 parts.