U of S | Mailing List Archive | alt-photo-process-l | Re: theoretical gum question

Re: theoretical gum question

I won't (because I can't!) go into the theory of this, it's really
complicated. (With all possible emulsion formulations and printing
work flows, almost indefinite combinations...)

My personal solution for printing gum with digital negatives was using
negatives calibrated for 2A+1B traditional cyanotype. Those negs work
pretty nicely for tricolor prints from separations and multi-layer
prints from the same negative. In short: I think you'll be OK with a
cyanotype curve and a density range something like log 1.4-1.5. Just
work out the necessary emulsion formulations and exposure times for
the relevant purposes... IF you want to keep it simple that is!

My 2c,

2009/9/9 Paul Viapiano <viapiano@pacbell.net>:
> If we try to match the negative to the paper/emulsion when making one-step
> gums, what does that bode for tri-color or multiple layered "mono"chromes
> from a single neg?
> Should each tricolor neg be matched the same way, or would we end up with
> mud, with so much heavy printing?
> Same with single neg type gums, should we use a longer scale neg knowing
> that we're going to print 3 or more times at different times/ratios/etc...?
> Paul