From: "Christina Z. Anderson" <zphoto@montana.net>
Subject: Re: APIS, hydroquinone hardening
Date: Wed, 13 Jul 2005 17:57:50 -0500
> BUT, presuming in a class of students where you are already teaching
> gum printing with dichromate, the use of di and a pinch of
> hydroquinone would seem to be less toxic than other
> choices...perhaps.
How real is this need and desire?
I found a compound that can harden gelatin (and a lot of other
polymers) very well and has manageable level of toxicity (again there
is no such thing as a safe hardener) with practically no odor or
volatile component. It can be used in mix-before-use style but it
comes with a couple of obvious inconvenience factors.
I'm about to test this compound for some of my emulsion projects, but
based on the chemical properties of this compound, I'd expect the
hardening to be fairly slow compared to glut, taking a day or two
after coating and drying to harden, and maybe a week to reach teh
maximum hardening effect at room temperature. This may be an advantage
for people who size paper in a large batch, but it is definitely a
concern for me.
More info to follow when I get enough experience with it.
Received on Fri Jul 22 15:35:46 2005
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