DOLLAND'S PROCESS A method of toning and intensifying platino type prints, worked out by A. W. Dolland. Its advantages are that it strengthens a weak platinum print, and at the same time changes it to a pure black or blue-black colour. The weak black picture to be strengthened and toned—the more recently made the better, as prints more than about ten weeks old are diffi cult to treat—is soaked in warm water and then laid face upwards on a sheet of warm glass. All superfluous water is blotted off, and a thin covering of glycerine is gently spread over the surface by means of the finger-tip or a broad camel-hair brush. A strong solution of gold chloride (i 5 grs. to 71 drms. of water) is then made up, and a few drops of it brushed over the glycerine-covered print as evenly as possible. The print soon begins to gain strength, and at the same time the colour of the print gradually changes to a warm black, then cold black, and finally blue-black. As soon as the desired effect
is attained the print is well washed in water in order to remove the gold and glycerine, care being taken during the treatment with gold that the high lights remain unaffected. After washing, and in order to ensure the reduction and elimination of any gold compounds which are liable to be formed with the sizing of the paper, the toned print should be sponged back and front with any clean-working alkaline developer, the formula specially recommended by Dolland being ; A. Metol. . . too grs. io g.
Sodium sulphite . z „ roo „ Water to • . zo oz. i,000 ccs.
B. Potass. carbonate zoo grs. g.
Water to . . 20 OZ. 1,000 ccs.
Use equal parts of A and B, and finally wash for about a quarter of an hour. All the above operations are best carried out in the strongest daylight possible.