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.
Prints Flat, Lacking Contrast. Generally due to overexposure; or, if the negative is a weak one, full of detail but very thin, you must use the regular grade of paper, as the regular grades develop more contrasty. A diluted developer will aid in producing contrast. Adding more bromide will produce increased contrast, but exercise care that you do not add too much. An over-supply of bromide produces green or brown tones.
Weak Prints (Lacking In Detail). This is generally caused by developer being too weak, or under-printing - perhaps under-developing. If the negative is weak, use the regular grade of paper with the same surface. It will produce more contrast. Prints from weak negatives are best developed in fresh full strength developer, fully timed, with plenty of bromide in the solution.
Mottled Shadows. This is generally caused by overprinting. Under-developing will also produce mottled shadows. Over-exposed prints, if developed far enough to overcome the mottled effect, would be too dark; therefore, make shorter exposure, so as to be able to develop fully, and this trouble will be overcome.
Prints Too Dark. This is generally caused by overexposure in printing and over-developing. Make shorter exposure and develop longer. Or, remove prints from the developer as soon as they are fully developed and get too dark. Properly exposed negatives will not develop too dark in the developer.
Small Yellow Or Purple Stains. This is generally caused by developer failing to spread evenly over the entire print; developing prints face down; surface of prints touching bottom of tray, or using trays that are not clean, and by prints being allowed to
Difficulties - Manipulating Velox Papers. 229 remain in the water too long before fixing, after developing. Prints that are not kept moving in hypo bath when first placed there will stain; air-bells gathering between surface of the print and hypo, when first placed in this bath, will cause yellow or purple stains; incomplete fixing will also cause these stains.
Yellow Stains All Over The Print. This is generally caused by under-printing and trying to force the print in development; prolonged development; developer too weak; not fixing long enough; insufficient washing after fixing will also cause this trouble. Always dip prints into the acid bath before fixing. Forcing development of an under-timed print will cause stains. In some cases it is due to the fact that the water contains too great a portion of iron. It is very easy to determine that the trouble is due to incomplete fixing, because in that event the print will have a sweet taste. Sea air will affect Velox paper, causing yellow whites; so packages should not be left open, and prints should be developed immediately after exposure.