Re: gum redevelopment

My position on "redevelopment" is that if the gum is properly hardened
it shouldn't be soluble once dry; to say the same thing another way, if
it IS soluble when dry, it hasn't been properly hardened. I live in a
damp climate and th idea of prints made of soluble gum makes me shudder,
but perhaps that's just me.

My prints withstand household ammonia as well as boiling water, but as
Keith says, nothing in a gum print will withstand bleach.

I was going to say there's a demonstration of this on the chemistry page
of my website, but then I remembered I haven't got that page up on the
site yet; it's still waiting on the mechanism of the crosslinking. But
my physical chemist consultant and I have made great progress this week
on that question, around the edges of funeral arrangements and
whatnot.
Katharine

Christina Z. Anderson wrote:
>
> Hi all,
> List has been somewhat quiet as of late, and since I'm not worried
> about editioning until I get as famous as Ansel Adams (aw gees, ya betcha as
> Minnesotans say), I thought I'd broach a different subject.
> How 'bout a poll to all you gum printers out there:
> It is sometimes suggested that after a print has dried completely, and
> even after some time, you can resoak and redevelop it, if needs be.
> Demachy said that the suggestion to do this is really a half truth, as,
> for one, the shadows are more soluble than the highlights in this state,
> etc. etc.
> My poll: how many of you use this technique? If so, are you using
> warm water and/or an alkali like ammonia or bleach? And how long after the
> print has been dried (e.g.1 day vs 2 weeks or whatever)? How often do you
> use it/how good a suggestion do you consider it?
> I personally find the suggestion promises more than it delivers. It
> wouldn't be my first suggestion of choice, which is why I am interested in
> hearing from those of you having success with this troubleshooting method.
> With ammonia (15ml to a liter of warm water on a month old print) it does
> solubilize the gum, but not as effectively as I would hope.
> Chris
Received on Mon Jul 12 01:13:51 2004