Hi Judy,
Well, knowing that this can be a sensitive issue with gum printers, let's
just say that I have been more impressed with the sharpness I have been able
to get with kallitype (or palladium or platinum), over straight gum
printing. I discovered that if I printed, for instance the C, M, and Y with
gum, and then used a noble salt for the black, the final impression was one
of a far more detailed print. I was printing gums over palladium, but due
to the cost, have tried to move over to kallitype.
Further: I am a recent convert to color gum printing. Thus, most of my
"source material" is in the form of medium and large format black and white
negatives. I have had good luck in enlarging these negatives (both with
digital means and with the Lawless method) in order to produce large
palladium and kallitype prints. But, after experiencing the subtle effects
of gum printing, I find these purely monochrome prints lacking. I AM
impressed, though with the "duotone" effect I get when I print, for
instance, a cold kallitype over a sepia gum. To get the same effect with
ONLY gum, I would have to print multiple layers of the "cold" color, which
is very hard to keep in register for large 16 x 20 and 20 x 24 prints.
Occasionally I will use a "soft" negative (soft as in slightly out of focus)
to print the lower contrast gum layer, and then pull it all together with a
very sharp, higher contrast kallitype layer. If I could achieve this with
gum alone, I probably would!
Here's one for you: I keep hearing about clearing out the "residual
dichromate stain". I've never had the need for this. Never. Usually, the
dichromate is the first to dissolve out of the print - often in as little as
a couple of minutes. Is this unusual?
-----Original Message-----
From: Judy Seigel [mailto:jseigel@panix.com]
Sent: Thursday, March 23, 2000 1:45 PM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: Gum vs. Kallitype
On Thu, 23 Mar 2000, Andre Fuhrmann wrote:
> Permawash, I take it, is a washaid. Washaids usually contain soda. Soda
> attacks gelatine. With standard silver prints this is not much of a
> problem as the gelatine is fairly tough and will survive a minute or two
> (but try 5 or even 10 minutes!). Glyoxal, however is not a very effective
> hardener. My advice: Clear the gum print in alun (may take 30 minutes or
> more) -- this will further harden the gelatine. Then let it rest for a
> couple of days. Omit step 5 and extend step 6.
Now just a darn minute, Andre -- you can't drop a line like that into our
tea party & then take off. What's this about "glyoxal is not a very
effective hardener"? You force me to take a leaf from Jeffery's book and
demand reference & source -- or at least a few particulars. I've been
doing some more tests on glyoxal, finding that length of hardening is a
factor. For instance, 5 minutes in glyoxal much better than 1 minute....
perhaps more is even better... Still, you probably mean less effective
than formaldehyde ... Can you add any ("evidentiary") details?
As for "clearing gum" in alum. Consensus of conservators seems to be that
alum bath degrades the color -- especially ye gods 30 minutes. (No I can't
document, but have read 5,627 times.)
HOWEVER, why clearing bath for gum anyway? Except in the RARE case when I
have done something really dumb, like leaving emulsion on paper overnight
in unairconditioned August, simple water soak (up to 2 hours) clears any
residual dichromate stain...
AND, isn't anybody going to ask Keith why he's putting VDB over gum? It's
a dark & lonely job, but someone has to do it, so here goes: Keith, tell
us why you're putting VDB over gum. I admit I tried it myself a couple of
times but got only a kind of murky brown. What did I miss? Maybe you're
putting only in areas? Or?
Judy
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