A coating for ordinary paper that is said to give green prints is made with a two per cent solution of gelatine, says Photography, and sensitized with the following solution:

Potassium Bichromate 15 gr. Magnesium Sulphate 25 gr. Water 1 oz.

This mixture is spread over the paper in the usual way and the paper dried in the dark. Printing is carried rather far. The print is washed, then surface dried or blotted off on a pad and laid film upwards on a sheet of glass, and the following developer is applied with a wad of cotton wool wrung out:

Pyrocatechin 5 gr. Water 1 oz.

The picture assumes a rich green color when developed, and is then washed for five or ten minutes and dried quickly by heat.