Re: Coating and lights
Judy Seigel (jseigel@panix.com)
Fri, 10 May 1996 02:12:21 -0400 (EDT)
On Thu, 9 May 1996, David Morrish wrote:
> I may be wrong, but wasn't there something I read about the sensitizers
> (especially gum) which *become* light sensitive when dry and are much
> less so when wet?
Yeah, you read it everywhere. Every article in print from here to 1900
says that. Mike Ware actually tested it...exposed wet gum emulsion with
saran wrap over it to protect negative. Then let dry and developed. It was
plenty light sensitive, he said.
However, room light is probably in a different spectral area. Also
it's further away and the inverse square of the amount under the
relative distance law applies. In any event, as noted, my tests show
ordinary room light is safe for coating gum, cyanotype, kallitype &
platinum. I dry in the dark -- a cul de sac with a curtain of darkroom
cloth enclosing it and a small electric fan in it.
Judy