RE: Re: Glyoxal Staining

While not yet a carbon printer, I have spent the last two years working
extensively with the gum process, using nothing but glyoxal as a hardening
agent. I have occasionally noticed a yellowing around the edges of the
paper, where it appears that the gelatin may have been thicker due to an
improper sizing (perhaps in the last few sheets of a batch where the gelatin
has cooled sufficiently to prevent proper run-off). BUT, this has only been
observed in sheets of Fabriano Artistico that have been lying around in the
studio (my other paper choice, Rives BFK, has never shown this effect). The
yellowing has never appeared in any finished gum photos. Perhaps the
extensive water soaking used in the gum process has helped.

-----Original Message-----
From: carbon-admin@opusis.com [mailto:carbon-admin@opusis.com]On Behalf
Of Lukas Werth
Sent: Friday, October 20, 2000 3:49 AM
To: carbon@opusis.com
Subject: Re: [Carbon] Re: Glyoxal Staining

I now regret having thrown away many of my initial gum/casein experiments
recently. The papers were all some months old.
All the papers which I sized for multiple exposures were hardened in
Glyoxal, without any bath afterwards, before coating the paper.
Reading this thread, I remember now that I noticed a stain on those papers
which I had sized, but not used for some reason. On the papers which I
coated and developed, however, even on those with only one coat, I don't
remember having detected any stain, even though I checked them all
carefully before discarding them (because I wanted to learn from initial
mistakes).

Could it be that a thorough water bath helps against glyoxal stain?

Lukas

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Received on Fri Oct 20 07:36:01 2000