RE: Chrome Alum Gelatin hardener

I'll second everything Clay says about the yellowing with glyoxal:
existence, stubborness to clear, and the fact that air seems to be a factor.
I've had partially covered sheets go yellow only where they were exposed to
the air. This in a dark room.

I use chrome alum to harden, and it is certainly not a cure for yellowing.
I recently discovered a stack of paper that I gelatin-coated 8 or so months
ago, and there were yellow streaks everywhere, even on the ones that were
buried deep in the stack. Upon close scrutiny, it appeared that the
yellowing was predominant in areas where the gelatin was thicker. As I
apply gelatin with a foam brush, it goes on uneven. I haven't tried using
this paper, or clearing it. If it ever warms up enough here in the Midworst
for me to resume printing, I'll try working with it. I'm a little nervous
though, because that is one big stack of yellowed paper I have on my
hands...

Keith

-----Original Message-----
From: wcharmon@wt.net [mailto:wcharmon@wt.net]
Sent: Sunday, February 08, 2004 3:31 PM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: Chrome Alum Gelatin hardener

Judy:
I definitely have experienced this, and very consistently at that. After
about
4-5 days, the sizing just goes yellow on me if I haven't taken it through
the
'wet steps' at least once. I tried getting rid of it with soaking, then some
bisulfite, and it just proved to be very stubborn and did not disappear once
it showed up. FWIW, it seems to be related to the amount of air to which the
print is exposed. The print on top of a stack always yellows first, followed
by the ones with the more restricted circulation. I suppose it is possible
that I have some bum glyoxal - I am working from the same bottle that I
bought
two or three years ago.

But yes, it has been real issue with me.

Clay
Received on Sun Feb 8 19:11:47 2004