> You are right for traditional printing, but you just can't calibrate gum
> printing accurately. I don't think you can even calibrate it
> inaccurately - it has a mind of it's own. Most folks are thrilled if
> they can develop some consistency.
David, I don't know what you mean when you say "calibrate gum printing":
To what? But when you say "consistency," I suppose you mean get repeatable
results. In my experience, tricolor printing in gum is much easier than
monochrome. I'd say also that results are eminently repeatable if you
watch the variables, which include the pigment and the maker, the gum, the
time before exposure, even the method of applying -- for instance whether
you sort of scrub in a coat or more or less flow it on -- as well of
course as the paper and what if any size has been put on it and how it was
applied. Not to mention what batch the paper was made in. (I even
suspect, though this I haven't tested, that how long ago the size was
applied is a variable.)
However,
1. I'd like to hear why anyone wants to make a gum print in literal
realistic color... (No doubt someone will make a good, or at least
passable, case.. so let her/him do it.)
2. The color in a gum print, other than being in pigment that's more
opaque than printers ink, is infinitely adjustable. In a tricolor print,
if you want more of a given color, add a second (or third!) coat in that
color. Or use more pigment in the first place. If there's too much color
in a coat, brush or soak it off. Or use less pigment to begin with. Some
printers add a black layer, some don't, and some add something like burnt
sienna, or other color that's not "process" color, etc.
3. As for "realistic" color.... Regular factory photo paper may in fact be
less "realistic" than a free-as-the-wind gum print; we've just learned to
accept that rendering as "real."
Judy