Re: Gelatin hardening question

Thanks, Tom, this is exactly the info I needed.

I wonder why all of a sudden this fact became apparent in the late 70's;
maybe there was a crossover between paper making and gum printing or
something then. I'm pretty sure the rest of the authors were just quoting
Crawford when they stated this info.

Heck, I saw Crawford at APIS, I should just try and ask him next APIS. I
was so surprised he was still alive, much less YOUNG, that I
was...questionless (hard to believe). I felt like I had encountered a rock
star :)
Chris

> "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 09:13:19 2004