Re: oil-print-glyoxal??

Katherine wrote:

>
>
>wasn't overly useful to the discussion, since it begs the question of
>doing something to retard mold growth; I just thought it was an
>interesting thing to throw into the mix.

Yes, it is. My main concern was mold - growth. In the oil process you
need the swelling of the gelatin, so you cannot harden after gelatine
size , or better : you cannot before inking.
I thought that the ink would prevent the mold-growth and a hardening
wasn't necessary (but then my original question: what about the
high-lights where nearly no ink is on the print)

>It wasn't actually intended as
>an answer to your original question, which I still think was a good
>question, but just as another bit of information to consider.
>
>But I'm not sure I understand this part of your comment, "The next
>question would be: why the hardening by gum-prints after sizing by
>gelatin. Isn't the purpose for this treatment also not to prevent
>mold-growth?"
>
>If you're asking why harden the gelatin by printing gum over it, I would
>say the purpose of hardening by gum prints is to make gum prints; the

Katherine, in your statement above you said :
'.............My comment about paper manufacturers not hardening
their size probably................'
I made several one-layer gum-prints directly on the paper without any
sizing in advance (see several gums on my web-site); ok , most of
these were for the paper-basket, but some are the niciest,
not-repeatables I ever made.

>incidental hardening of the underlying size, and consequent prevention
>of mold growth in the underlying size, is an added bonus. Whether it
>hardens the gelatin clear through in areas of light tone is an open
question of course that I don't have an answer to.
>If you're asking the more general question, whether the purpose of
>hardening a gelatin size isn't to prevent mold growth, that's what I
>always thought the purpose of hardening gelatin was, but I'm told by
>other gum printers (see Kate's comment) that they harden the size
>because unhardened size doesn't prevent pigment stain for them. Since I
>don't have a problem with pigment stain, with either unsized paper,
>unhardened size, or hardened size (except for a couple of papers that
>are inherently prone to speckling, like Arches) I can't add anything to
>that part of the discussion.

But I am happy with the comments you made; but what about the ARCHES
papers. I have the impression that the Rives BFK of some years ago
isn't the same I use now a days. (or my notes are clumsy...)
It is maybe the same as the Fabriano-papers; but at least they give
new names to changed papers.
Cheers,
Henk

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H e n k  T h i j s  -  P h o t o g r a p h y
photography     http://www.thijs-foto.com
member of F68   http://www.f68.nl
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