Another problem is maintaining registration for multiple exposures. Paper
fibers contract and expand when soaked and dried. I would imagine that
registration would be difficult in an easel or whatever method was used.
I ran into problems similar to this in just trying to create internegatives
from 35mm to 10x12 graphic film. Some emulsions, as the graphics film and
in this case dichromate is sensitive toward the ultraviolet spectrum. I
experimented with photoflood lamps but even the higher wattage output is not
enough, not to speak of the increased heat in the enlarger.
Hopefully, if we discuss the matter further, we may arrive at a method for
using an enlarger to produce multi/exposure/color gum prints. Hope to here
something back.
Jim Boyd
U.S. Atlantic Command
Joint Training, Analysis and Simulation Center