Re: Gelatin hardening question

From: Tom Ferguson ^lt;tomf2468@pipeline.com>
Date: 07/17/04-08:19:40 AM Z
Message-id: <5753CAD6-D7FC-11D8-9893-000502D77DA6@pipeline.com>

"Common Wisdom" in the hand papermaking world is that Chrome Alum is
non archival to the paper fibers themselves. Not terrible, just not
good. It is said to "slightly" harden and "slightly" yellow the paper
over a long period of time.

 From Bernard Toale's "The Art of Papermaking" (a standard in the
field): "Alum and rosin are a traditional European duo for sizing. They
produce an archivally unstable sheet with a PH of 4.5. They should not
be used" (page 54)

With gum printing, most of us start with factory sized paper. So, the
gum/alum mix would be more of a coating, and that coating gets
partially removed in the washing. So, for gum I would "ASSUME" the
word "slightly" in my first paragraph could be changed to "very
slightly".

None of this has anything to do with possible damage to the "image",
just the paper fibers.

I'll stay with glyoxal.

On Friday, July 16, 2004, at 10:27 PM, Christina Z. Anderson wrote:

>> Judy said: I have seen several references to "formalin" in early 20th
> century
>> literature, one might even have been Demachy.
>
> Out of, let's say, 50 sizing recipes before the 1940's, only 5 were
> formalin/formaldehyde hardened. Demachy did not size, or, at least, he
> never felt the need to do so, he says. However, I found later a
> reference
> to his size for oil printing--gelatin hardened with chrome alum.
>
> Use of formaldehyde was as far back as 1900, though (Abbott).
>
> There are many size recipes I have compiled, just for interest.
> Starch,
> gelatin, gum, even fish glue and methylated spirit combined, and venice
> turpentine, elmer's glue, gesso, acrylic, etc. etc. Many of the size
> recipes for starch and gelatin do not have an added hardener, but the
> most
> common hardener is chrome alum.
>
> The first mention I have of a problem with chrome alum, aside from
> graininess or shrinking paper, is Crawford in 1979. Then a number of
> other
> authors ditto this: Scopick, Arnow, Reeves, James, etc.
>
> I don't know where this info came from first (in other words, what
> Crawford's source is, as I think the subsequent authors may have
> sourced
> him, at least, Scopick did). Anyone have any more info on the
> archivalness
> of chrome alum?
> Chris
>
>
>
--------------
Tom Ferguson
http://www.ferguson-photo-design.com
Received on Sat Jul 17 08:21:44 2004

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