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.
Tone Of Print Brown. Brown tones are caused by overexposure and excessive use of bromide. Learn to print to the proper depth, and be careful not to use too much bromide, but just enough to obtain clear whites.
Tone Blue-Black, Whites Having A Grayish Tint. A certain sign that not enough bromide was used.
Too Much Contrast. This difficulty you can overcome by being careful to use a soft grade of paper for a contrasty negative; also by using full strength developer, printing portions of negative which are too strong longer than the parts which print dark. To do this, interpose a cardboard for a few seconds between the light and the portion of the negative you want to hold back during printing.
No Contrast. For flat negatives use a contrasty grade of paper. Cut down the exposures and develop in weak developer. Oftentimes it is necessary to add a little more bromide, as it will help to produce contrast.
Prints Turn Brown In Hypo Bath. If a print turns brown in a hypo bath, there is being produced what is called a sulphur tone. This shows that the fixing bath is not balanced properly, evidently being too strong in both acetic acid and alum. If prints are left in the bath over night they will become quite brown. A bath of this kind should be discarded, or more water and hypo added. The cause of the bath toning brown is that the acid releases the sulphur from the hyposulphite of soda, causing a sulphurization.
Prints Yellow And Bleached After Treating With A Little Red Prussiate Solution. This trouble results from using the solution too strong. Employ a weak solution and this difficulty will readily be overcome.
Edges Of Vignette Bleaching Too Rapidly When Using The Chloride Of Lime. Care must be exercised in using the chloride of lime. If you are applying it with a tuft of cotton, be sure there is not too much chloride of lime solution on the cotton, but just enough to wet it and no more. When reduction has proceeded far enough, place immediately in water.
Chloride Of Lime Solution Not Reducing Or Clearing The Whites. Solution is probably not strong enough. Strengthen by adding more of the chloride of lime. Rubbing just a little bit harder with a tuft of cotton will hasten the reduction.