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.
The difficulties which we have already enumerated for col-lodio carbon black and white will, in most cases, apply to the sepia toning. The following however are a number of difficulties which apply directly to sepia toning.
Prints Too Cold In Tone. This is simply because you toned a trifle too far - allowed your prints to remain too long in the toning bath. Remember that the prints in drying down become about two shades colder than they appeared when wet.
Highlights Clear But Shadows Not Toned. This would indicate a bath too acid. Use more alkali. If your bath is properly prepared and the prints correctly washed before toning, you should have no trouble. The only way to overcome this difficulty is to use great care both in the washing of the prints and the preparing of the baths. Also employ enough alkali to restrain the highlights from bleaching until the shadows are toned.
Judging When Prints Have Toned Sufficiently. Watch the highlights, the whites, and the whitest parts of the print. When these are clear and mellow - not bleached - the prints are toned, regardless of the red in the shadows. This is, of course, governed almost entirely by the amount of preliminary washing and the proper amount of alkali in the toning bath.
Retaining Warm Tone. Do not overlook the fact that your prints will tone down considerably when drying. Take them out of the toning bath a trifle warmer than you would desire to have the finished print and there will be no trouble in retaining the warm tone.
Prints Bleaching In Hypo. If the prints bleach in hypo it is a certain sign that either the hypo bath is much too strong, or it is acid. Hypo bath for sepia prints should not be so strong as for black and white - if acid neutralize with borax.
Prints Sulphurizing. Prints that are not properly washed before toning, thereby carrying acid into the toning bath, are apt to sulphurize. If the hypo is acid the prints are likely to sulphurize. See that your prints are properly washed and that your hypo tests neutral or slightly alkaline. If you are producing the sepia tone in the platinum bath only, carefully test the last wash water before you place prints in the hypo. See that this water is neutral or slightly alkaline. There will then be no danger of carrying acid from the platinum into the hypo, causing sul-phurization.
Streaks In Prints Before Toning. This shows either insufficient washing or that the prints have been stacked together for too long a time without separating.
Streaks In Prints After Fixing. If you allow prints to remain in the hypo, failing to separate them often enough, streaks are apt to be produced more especially if the hypo bath should be acid. Prints Lacking Brilliancy. This is almost a certain sign that your manipulation, toning, washing, etc. (more especially the washing), were too slow.
498. Purple Tones. Obtaining Too Deep a Purple Tone.- This is because you carried your toning a trifle too far. Allow for the fact that the fixing and drying down of the prints will cause the tone to become a few shades colder.
Prints Toning Too Slow. If the prints tone too slowly add a trifle more neutralized gold.
Prints Toning Too Fast. Reduce the strength of the bath by adding more water.