In commencing to tone, place a few ounces of water in the dish, and add an equal quantity of the stock solution, and if the toning begins to flag a little, add more of it from time to time.
With the resin processes over-toning is to be carefully avoided.
Resinized paper may be obtained from most photographic dealers, we believe, and for some purposes is an admirable substitute for albumenized paper.
[CHAPTER XX.]
PRINTING ON GELATINO-CHLORIDE EMULSION PAPER.
Mr. W. T. Wilkinson has recently brought forward the notion of using gelatine instead of albumen as a medium for holding the silver chloride in printing. He uses the following formula:—
| Barium chloride | 2,440 | grains |
| Gelatine | 2,000 | " |
| Water | 20 | ounces |
The gelatine is allowed to swell in the water, and, by the aid of heat, is dissolved; the barium chloride is then added. Next he prepares—
| Silver nitrate | 1,700 | grains |
| Water | 5 | ounces |
and adds this to the former, little by little, in a large bottle with much shaking, or pours it slowly into the former in a large jar, stirring briskly the whole time. This makes an emulsion of silver chloride, and is used without washing. When required for use, the gelatine, which will have set when cold, is swelled by placing the jar containing it in hot water, and is then transferred to a dish. The dish should be kept warm by being placed, supported on small blocks, in a tin tray (about two inches larger in dimensions every way than the dish) filled with hot water, the temperature of which should be about 150° F. to commence with. Saxe or Rive paper may be coated by rolling the sheet face outwards, and placing the edge of the roll upon the gelatine. The two corners of the paper in contact with the solution are then taken hold of by the fingers, and raised. The paper will unroll of itself, and take up a thin layer of the gelatine emulsion. The sheet of paper is then suspended to dry. All these operations are, of course, conducted in the dark room. The behaviour of the paper in the printing-frame is precisely the same as albumenized paper, and the washing and toning are conducted in the same way. For a fixing bath is used—