For processes not using light sensitive silver salts one can, in practice,
working quickly, coat, without fogging the final print, in any light other
than direct sunlight or light of similar intensity. This includes indirect
daylight, flourescent light, or incandescent bulbs, But everybody will
feel happier if you work in subdued light avoiding those sources rich in
UV. But get the sensitised paper into the dark to dry as soon as possible.
As to fogging from 'old' ferric oxalate, I am using ferrric oxalate
solution of my own manufacture which is eighteen months old. I do not get
fogged prints. When I do I will stop using it.
Terry King
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