Spread on the copper object a solution composed of:
| Acetate or chlorhydrate of ammonia | 30 parts |
| Sea salt | 10 parts |
| Cream of tartar | 10 parts |
| Acetate of copper | 10 parts |
| Diluted acetic acid | 100 parts |
Let dry for 24 to 48 hours at an ordinary temperature. The surface of the metal will become covered with a series of varying tints. Brush with a waxed brush. The green portions soaked with chlorhydrate of ammonia will assume a blue coloring, and those treated with carbonate will be thick and darkened.