Wayde Allen (wallen@boulder.nist.gov)
Wed, 03 Nov 1999 09:02:32 -0700 (MST)
On Tue, 2 Nov 1999, Carl Weese wrote:
> The really interesting part is that the water isn't even "soft": it's
> "moderately hard." This is why my speculation is that some trace mineral
> in there is nullifying whatever the built-in hardening agent is rather
> than directly softening the gelatin, because any standard hardening
> fixer works just fine. Even long silver-gelatin fiber-base wash times do
> not cause any trouble to the hardened prints. You can use Kodak Rapid
> Fix with 1/2 the maximum hardening agent in it and do long washes with
> impunity. But with no hardening agent, even the shortest soak time (a la
> Ilford quick wash method) leaves prints so soft they stick to or emboss
> from the drying screen.---Carl
Interesting indeed!
Embossing or sticking to the drying screen certainly implies that the wet
gelatin film is softer than you would like. This is affected by the pH of
the water among other things. Like I said before, hardening should
improve the toughness of the wet gelatin emulsion, and help with the
problem you are describing above. I'm still not so certain that it
implies that the abrasion resistance of the dried film is much greater
however. Maybe, but...
- Wayde
(wallen@boulder.nist.gov)
This archive was generated by hypermail 2.0b3 on Sun Dec 05 1999 - 17:09:23