U of S | Mailing List Archive | alt-photo-process-l | Re: Gum Humidity Question

Re: Gum Humidity Question

On Sep 26, 2006, at 8:48 PM, Christina Z. Anderson wrote

Down in SC I would notice spontaneous hardening of emulsion from the first
to the last gum print when I was doing 9 at a time; here I can go a very
long time (did 13 at once this weekend) and no noticeable effect on prints
at the 33% humidity level.
Chris, I'm curious why you refer to this as "spontaneous hardening" rather than "dark reaction." Dark reaction has an even steeper relationship to humidity than speed of the light reaction does; for gum the relationship is close to vertical, for this reason I never let coated paper sit around in my humid environment.