53. Other Supports

Other Supports. This process may be applied to silk or any fabric, also to wood or leather. The methods employed are practically the same as those for manipulating paper.

54. Preparing The Sizing And Salting Bath

Preparing The Sizing And Salting Bath. Ready sized and salted paper may be purchased from photographic supply dealers, and when obtainable we recommend its purchase. The sizing consists of some alkaline chloride combined with a small quantity of gelatin, or arrow-root. The viscous substance covers the surface of the paper and keeps the salting from penetrating into its pores.

55. The following formula is a very effective sizing bath, and answers practically every purpose:

Crystallized Ammonium Chloride.......

130

grs.

Re-crystallized Sodium Carbonate.............

200

grs.

Citric Acid............................

60

grs.

Arrow-root........................

160

grs.

Water.............................

20

ozs.

56. There will be practically no necessity for altering this formula, providing negatives from which you print are of good, even quality. There may be times, however, when it will be necessary to modify the solution. For instance, if you are desirous of securing softer results use about one-half the above amount of ammonium chloride; while if printing from flat negatives and you desire to produce more contrast, increase the amount of ammonium chloride to about double that called for in the above formula. In mixing the various chemicals the arrow-root should be first worked into a thin paste by adding to it a very small quantity of water (about 1 ounce); then add 15 ounces of water and heat it slowly to almost the boiling point, but never allow the solution to boil, as this will invariably cause air-bubbles to be formed. When the solution has become quite clear it should be allowed to cool.

57. In another small vessel place the three quantities of crystals and add the remainder of the water. Use cold water and allow these crystals to dissolve without agitation, for combining the sodium carbonate and citric acid causes the mixture to effervesce and if stirred it would overflow. When the arrow-root solution has cooled, pour the dissolved crystal solution into it. The combined salting and sizing solution is now ready for use.

58. Another good formula is as follows:

Ammonium Chloride..............

70

grs,

Sodium Citrate..........................

100

grs,

Sodium Chloride.......................

35

grs,

Gelatin.........................

10

grs,

Distilled Water.................................

10

ozs

The gelatin should be washed in two or three changes of cold water and then allowed to dissolve in warm water, when the remaining components of the formula may be added. Filter the solution and use while warm. The paper to be salted should be floated on this solution for three minutes.