Any gelatino-chloride paper may be slightly printed and afterwards developed. The great drawback to the process is the liability of obtaining degraded high lights with a consequent flattening and fogging of the image; because if the faint image from a brief exposure under a negative can be developed into a dark print, any chance exposure of the paper to daylight will show by fog and degradation. If the paper has been properly protected from extraneous light and is otherwise suitable, development has a tendency to intensify the contrasts, therefore a little fog is sometimes an advantage unless allowance has been made in the negative. Eastmans', Paget, and Otto gelatino-chloride paper can be recommended for this process. Print a faint image in diffused light-that is, expose for about five minutes to daylight or one hour at 6 in. from an incandescent gaslight. Make up the following solutions: - No. 1. Hydroquinone 25 gr., metol 10 gr., sulphite of soda 25 gr., potassium bromide 50 gr., ammonium bromide 100 gr., water 8 oz. No. 2. Sodium hydrate 15 gr., water 2 oz. No. 3. Tannic acid 8 gr., water 1 oz. Take thirty-two parts of No. 1, eight parts of No. 2, and one part of No. 3. Immerse the print without washing. It rapidly bleaches to a light yellow, then slowly increases in density.

When nearly dark enough, remove the print and place it in a 1 in 60 solution of acetic acid, and thoroughly wash for ten minutes. Great care must be taken to wash out all the acid, or uneven tones will result. The print may then be toned in the ordinary sulpho-cyanide bath and fixed as usual. Avoid handling the paper or stains will result. Another method by which prints of a fairly satisfactory colour may be obtained without toning consists of pouring over the dry print a solution of pyro 1 gr., bichromate of potash solution (1 gr. in 2 oz.) 10 minims, water 1 oz.; a print of a sepia tone results. But it is difficult to avoid degraded high lights; it is, in fact, practically impossible if a larger proportion of bichromate solution than that given above is used. An acid fixing bath has been recommended.