Re: Fugitive Pigments

One thing that may prove not to worry about fugitive pigments in sunlight:
it was mentioned a number of times in the German literature on gum printing
not to use a chemical clear to get rid of dichromate stain. Instead, it was
recommended to leave a finished print out in sunlight for a day, which would
change the brown chrome super oxide into a weak gray green chrome oxide,
"which does not bother much any more". I couldn't believe this was the case
until I tried it, and yes, it works. You can test it by taking just
dichromate coated paper and exposing it to your negative, develop it out in
water and then dry it out in the sun and watch your nice brown image
disappear into a pale gray green in a short period of time. This was a
problem Mongo Ponton had, too, when he discovered dichromate on paper as a
printing method in 1839--he couldn't preserve the brown image, as it would
fade.

The other more recommended way was to soak a finished and already dried
print in water for a day, and then also chemicals were recommended as a last
resort--alum, sulfuric acid, sodium sulfite, etc.

Anyway, that was a long aside, but it seemed that the worry about fading of
pigments was not an issue with this method. Then again, they probably
weren't using alizarin crimson...
Chris
Received on Tue Jul 26 13:37:17 2005