This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Note. The speed of Carbon Black paper makes it suitable for enlarging purposes, the resulting prints having a richness and depth unequaled by any of the bromide papers. For enlarging, use an arc lamp and condensing lenses.
Matte - Regular Weight - Surface having slight grain and slight lustre.
Medium Rough - Heavy Stock - Rough surface with slight lustre.
Extra Heavy - Double Weight - Smooth half-matte surface.
994. Carbon Green is the slowest brand of Artura paper. It will require 20 to 30 seconds exposure to north daylight with the average negative. Development may be carried on in yellow artificial light without danger of fogging. After becoming familiar with the speed of the paper, it is simply necessary to judge the density of the different negatives. For the beginner a test should be made by covering some important part of the negative with a small piece of paper and exposing it to the light. When exposure is thought to be sufficient, remove the test strip and develop it. If exposure is correct, the image will develop to the desired depth and stop. If the image stops developing before the desired depth is reached, it will indicate under-exposure. If development proceeds beyond the desired depth before development stops, it will indicate over-exposure.
. 14 grs.
Sulphite of Soda (Dry)......................
Carbonate of Soda (Dry)......................................
996. When ready to develop add one drop of a saturated solution of bromide of potash to each ounce of developer. Chemicals should be dissolved in the order given, thoroughly dissolving each before adding the next. If sodas in crystal form are used, double the amount given in above formula.
997. Prints may be wet in water previous to development. This, however, is not necessary. Immerse prints quickly and evenly in the developer, removing air-bells that may have formed, by rubbing the surface of the print with the tips of the fingers, or a tuft of cotton. A properly exposed print will develop to the desired depth and stop. The first action of Carbon Green paper in the developer is quick, after which the image builds up more slowly. Prints should be timed, so they may be allowed to remain in the developer until development is completely stopped. Overexposure and under-development will cause tones not as pleasing as those obtained by full development. If prints are too dark, give less exposure. The image will appear quickly and develop about half way. The development will then pause and proceed slowly to the stopping point.
998. When a print is completely developed it will stop in development. If a print is under-exposed and over-developed, or forced, it will lack richness and also be apt to have impure or fogged whites. If a print is over-exposed and under-developed it will have reached the desired depth before development has stopped. An under-developed print will be muddy in general appearance. To obtain the best color or tone on Carbon Green paper it is important to observe the foregoing suggestions in regard to giving prints full development. The developer formula, as given, will prove satisfactory for the ordinary run of negatives. When negatives are inclined to be flat, the contrast of the paper can be increased to a certain extent by using additional bromide of potash in the developer. Normal and contrasty negatives will produce excellent prints on Carbon Green paper without special treatment. After prints are developed, rinse in water and transfer immediately to the fixing bath. Be sure to quickly and thoroughly immerse the print in the fixing bath. Fix prints face up to prevent air-bells from forming on the surface of the print. (See Paragraphs 977 and 978 for fixing bath formula).
999. Fix prints about 10 minutes, or until the yellow color is removed from the film. Prolonged fixing should be avoided, as it sometimes affects the tone of the print. After prints are fixed, wash as usual for one hour in running water. If difficulty arises look under head of General Information for suggestions. For instructions in regard to mounting or drying see General Information.