yellow gelatin

On Mon, 22 Mar 2004, Christina Z. Anderson wrote:
>
> Now this is interesting. So what I deduce from this is glyoxal yellows with
> age. However, it worked great still with the 40 sheets I sized before this
> batch, and there is no sign of yellowing on the paper to any degree. So
> maybe this isn't a biggie.
> Chris

Christina, my old stock glyoxal tends to look yellow, but it doesn't look
yellow in the working solution-- which is after all only 15 cc/liter.
However that working solution turns VERY yellow or orange when you put an
alkali in it -- as is recommended for uplinking. I tried all the alkalis
& found one that didn't yellow it so much-- I think it was bicarb... but
then I gave it up, deciding my gelatin is linked enough.

And, as I've mentioned, it doesn't turn yellow when I rinse it after the
hardening bath. But maybe your *gelatin* had some alkali in it. What
kind was it?

PS. and to think that the Pictorialists added a special coat with orange
and other colors to give a golden/yellow *tone* to the paper !

Judy
Received on Tue Mar 23 03:47:20 2004