Re: Deionised ossein

Judy Seigel (jseigel@panix.com)
Sun, 23 Jun 1996 02:13:25 -0400 (EDT)

On Sun, 23 Jun 1996, TERRY KING wrote:
>> .... why do you dry the gelatine immediately? To keep it on
> the surface? If so, why?"
>
> No, it is important to dry the gelatine so that it does not gel on the surface
> of the paper where it can dissolve away taking your image with it..

OK Terry, one of us is, as we say, a sandwich short of a picnic. I do not
preclude the possibility that it is I, but I do not expect it either.

Whatever, your "explanation" above is contrary to my understanding and
experience. First of all, I have never seen *any* gelatine "gel" on the
surface, except in a cold room in winter, say, below 65 degrees F. But if
I were deliberately trying to get gelatine to gel on the surface in
summertime, the best way to do that would be to dry it rapidly with heat
-- tho I doubt I could anyway.

In my tests with Knox (about 200 bloom, I'm told), 300 bloom pigskin and
the 260 bloom ossein, BTW, *all* sink nicely into the paper when applied
warm (about 100 to 120 F) in a warm room (75F).

Nor am I convinced that gelatine on surface "dissolves" faster than when
sunk into paper, tho I suppose it could float off -- but that would have
to be some gob of gelatine...

> Purified water is what pharmacists use. It has the impurities removed by reverse
> osmosis rather than by distillation. It tends to be sustantially cheaper
> especially from health food shops. The purified water is of course not intended
> for gum but 'solution' processes such as salt, kallitype and platinum.

We pay about a dollar a gallon for distilled water in the supermarket...

Judy