RE: archivalness of gum
oh, now I remember we had a discussion on this years ago. I think it was I
who asked exactly the same question, and you were the one who gave the
I am getting old. :-)
> -----Original Message-----
> From: Ryuji Suzuki [mailto:firstname.lastname@example.org]
> Sent: Friday, December 21, 2007 1:51 PM
> To: email@example.com
> Subject: Re: archivalness of gum
> From: Dave S <firstname.lastname@example.org>
> Subject: RE: archivalness of gum
> Date: Fri, 21 Dec 2007 11:04:09 -0500
> > Ok, mybe in a less technical sense, does hardening reduce
> or minimize
> > the problem with bugs?
> > I have always thought (though I have no scientific proof and didn't
> > check) that the hardened gelatin would capture less water from the
> > atmosphere and so would preserve better... sort of like a
> jello would
> > certainly spoil faster than the dry gelatin powder. Is this
> not true?
> Hardener only suppresses swelling of gelatin when the gelatin
> is soaking wet or half wet. Once dried, the ability of
> gelatin to exchange moisture with air is mostly determined by
> the air temperature, humidity and the plasticizers used in
> the gelatin coating, if any. Hardener has little or no
> influence on this.
> Also, hardener molecules are tightly bound to the host
> macromolecules and not really free to act as biocide as you
> would expect from free aldehydes.
> If you want to protect gelatin from fungi you should use
> suitable humidity control. A RH of 30% is very good.
> Another approach may be to use a fungicide treatment of the
> image. I was asked by several people to offer such a product
> (Tetenal made a final rinse solution containing a biocide, for
> example) but I was reluctant to do so. Fungicide may prevent
> fungus but high humidity is not a desirable condition for the
> image permanence even if fungus problem does not occur.
> Humidity control, while potentially expensive depending on
> the region, is the best overall solution.
> Ryuji Suzuki
> "Patriotism is the last refuge to which a scoundrel clings."
> (Bob Dylan, Sweetheart Like You, 1983)