Re: Gum Humidity Question

[Katharine Thayer <kthayer@pacifier.com>]

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.
kt