TEAR DROPS OR DRYING MARKS . If drops of water are left on the film during drying, and especially if the drying temperature is excessive, the gelatin does not shrink uniformly, and markings are produced. If plates and films are wiped carefully with a soft sponge or chamois, and allowed to drain a few minutes before the drying air is turned on, formation of these markings can be prevented.
Photographic troubles will be few, and costly retakes largely avoided, if the user of photographic solutions will purchase pure chemicals, mix them according to directions, maintain temperatures at 65-70° F (18-21° C), replace used baths before they become overworked, and agitate films, plates, and papers sufficiently when immersing them in any solution.
Trays, tanks, film hangers, and all other equipment should be cleaned regularly and kept in a definite place when not in use. Dry chemicals and stock solutions should be kept covered to prevent access of dust.
1. CRABTREE J. I., and MATTHEWS G. E., "Modern Darkroom Practice," J. Biol. Phot. Assoc., 1934, 2, 197-207.
2. Photographic Chemicals and Solutions, Am. Phot. Pub. Co., Boston, 1939.
3. CHABTREE J. I., MATTHEWS G. E., and MUEHLER L. E., Materials for the Construction of Photographic Processing Apparatus, Eastman Kodak Co., Rochester, N. Y., 1943.
4. EASTMAN KODAK Co., Elementary Photographic Chemistry, Rochester, N. Y., 1943.
5. Motion Picture Laboratory Practice and Characteristics of Eastman Motion Picture Films, Rochester, N. Y., 1936.
6. Commercial Photofinishing, Rochester, N. Y., 1944.
7. KODAK, LTD., The Illumination of Photographic Workrooms, London.
8. PARKER J. H., "Darkroom Design and Equipment," J. Phot. Soc. Am., 1940, 6, 9-16, et. seq.
9. "Darkroom Arrangement," Complete Photographer, 1942, 3, 1146-63.
The books on general practice listed at the end of Chapter II should be consulted also.