This paper which is made by precipitating Chloride of Silver in a solution of Gelatine so as to make what is technically called an emulsion, and coating paper with the same, will in many instances give much finer results than the ordinary sensitized printing paper, which is coated with salted albumen, and sensitized on a solution of Nitrate of Silver. From the character of the coating of the paper, it yields prints which possess much greater contrast and detail in the shadows, and is, for this reason, especially useful for thin or flat negatives wanting in these characteristics For those negatives possessing great contrast the ordinary albumenized paper will give better results. . The Gelatino-Chloride paper is printed in precisely the same manner as the ordinary paper, as directed on page 33; but the depth of colour should be rather deeper in the finished print as it loses somewhat more in toning and fixing. Care must be exercised as this paper is rather more liable to become discoloured and stained. The prints require a slightly different method of toning, and the following may be considered as the best process to adopt. The prints must be thoroughly well washed in several changes of water, and then soaked in solution of alum (1 in 20) for five minutes, and again washed and transferred to one of the following baths: -
Chloride of Gold ......... 3 grains.
Potassium Sulphocyanide...... 36 ,,
Hyposulphite of Soda ... ... 1½
Distilled Water ......... 12 ounces.
This gives purplish-brown tones of great beauty and richness of colour.
Acetate of Soda ......... 1 ounce.
Chloride of Gold ... ...... 10 grains.
Distilled Water ... ... ... 25 ounces.
Ammonium Sulphocyanide ... 120 grains.
Chloride of Gold ....., ... 5 „
Distilled Water ......... 10 ounces.
These solutions will keep well separately; and for use must be mixed in the proportion of 3 ounces of b to 10 ounces of a. This also gives good purplish tones.
Ammonium Sulphocyanide ... ½ ounce.
Alum ••• ••• ••• ••• • •• ½ "
Ammtmium Carbonate ...... 2 grains.
Distilled Water ......... 25 ounces.
Chloride of Gold......... 3 grains.
Distilled Water ......... 20 ounces.
Mix by pouring 3 parts of b into 4 parts of a stirring constantly. This gives fine chestnut-brown tones, free from any bluish tint. If used more concentrated it will give blacker tones.
Combined Toning and Fixing Bath.
Hypo ... ... ...... 6 ounces.
Sulphocyanide of Potash...... 1 „
Acetate of Soda ......... 1½ ,,
Alum ............ 96 grains.
Distilled Water ......... 21 ounces.
Fill the bottle containing this solution with scraps and clippings of spoilt prints, or add 100 grains of Chloride of Silver, and leave for twenty-four hours, and add
Chloride of Gold ... ... ... 15 grains .
Chloride of Ammonium...... 30 .,
Distilled Water ... ... ... 6 ounces.
When placed in this bath the prints turn bright yellow, and run through the scale of colours to a brilliant purplish-black. The preliminary alum bath is not required.
Hypo... ... ... ... ... 3 ounces.
Chloride of Gold ... ... ... 6 grains.
Lead Nitrate.......... 3 grains.
Distilled Water ... ... ... 20 ounces.
The prints should be placed in this without being washed previously.
After toning, the prints should be washed once in clean water, and passed into the following
Hypo ... ...... ... ... 1 ounce.
Water ... ... ... ... 10 „ and allowed to remain for at least five minutes, and then washed thoroughly with frequent changes of water for at least an hour.
All toning baths should be mixed at least twelve hours before being used. The tone of the prints must be judged by holding them up to the light and looking through them. Extreme care must be exercised that greasy or hypo contaminated fingers do not touch the prints. If the prints refuse to tone in well defined spots, grease or hypo must be suspected; if in irregular patches with ill-defined outlines, the prints must be soaked in the alum bath for a longer period. If the edges turn greyish-blue or blue before the body of the print, the toning bath is too strong and more water must be added.
Prints on Gelatino-Chloride Paper may be treated in exactly the same way as ordinary albumen prints, but they should be trimmed before becoming quite dry, and mounted with fresh starch paste or gelatine, or by means of the indiarubber solution (page 78). When mounted, the face of the prints should be gently rubbed with a clean moist wash-leather. Blotting paper must not be used. A very high gloss may be obtained by the following process: -
A perfectly clean piece of glass, preferably of patent plate, a cutting glass answers well, quarter of an inch larger all round than the print to be dried should be selected, and in the centre of this pour a small pool of the following solution:-
Yellow Resin ......... 36 grains.
Yellow Wax ........ 12 „
Turpentine or Ether ...... 2 ounces.
Rub this all over the plate with a tuft of cotton wool till dry, and then polish with a clean piece of wool. Immerse the print and glass into a dish of cold water, and bring the print face downwards on to the waxed glass; raise from the water, and by aid of a squeegee, bring both into intimate contact; raise the glass bearing the print, and examine through the glass for any air bubbles, which may now be easily detected; if any are visible a piece of clean dry paper or indiarubber cloth should be placed over the print, and the squeegee again used till no bubbles are seen. Sheet vulcanite may also be used, or that known as Ferrotype Plates, these require no waxing until they have been used for some time. Rear the glass bearing the print on end to dry, and when thoroughly dry one corner may be raised from the glass with a penknife and the print easily stripped from its support. To mount these prints they should receive before thoroughly drying a good coating of fresh stiff paste, and the cards should be damped and the prints applied; but it must be understood that the print is stripped before being mounted. If there is any difficulty in stripping a print it should be placed for a few seconds before the fire, when they will generally leave their support of their own accord. Matt or dead surface prints may be obtained by treating ground glass with the wax solution and treating as described above.