Re: GUM PRINTING QUESTION

> It's an empirical question of course, whether the yellow dichromate
> stain would turn brown over time, and could be tested by someone who's
> interested, by putting one of these yellow dichromate-stained prints in
> the sun and seeing what happens. If it stays yellow, that would be
> somewhat astonishing but a good thing to know.

I did this last summer and we had a discussion on this then; yes, the sun,
in fact, does bleach the yellow dichromate out of the print. All one has to
do is put the print outside, cover half, and see the tone change. Better
yet, expose and develop a print with just gum and dichromate, and put it
outside and watch it disappear to a pale green.

It was one method used in the old books (well lo and behold) to "clear" a
print of yellow dichromate stain. Didn't I just share that piece of
information here this month??

It also convinced me that once the print is exposed and developed in water,
what remains does not in fact turn dark or ruin a print. In fact, again, in
old literature, clearing was always optional. I no longer clear. With my
lower dichromate amount that I use (3/4 less am di than I used to) I no
longer need to.

There is nothing new under the sun it seems...literally and figuratively.
Regards,
Chris
Received on Wed Aug 10 11:57:05 2005