From: Judy Seigel (jseigel@panix.com)
Date: 11/11/01-12:46:53 AM Z
On Sat, 10 Nov 2001 FotoDave@aol.com wrote:
> ..The main issue is that gum printing is a direct (non
> transfer) process, so the speed and contrast depends on the thickness of the
> coating.
I'd say not necessarily... because there's so much variation possible in
the balance of the three ingredients (gum, pigment, dichromate)... I can
alter both speed and contrast by altering values of one or more of those,
and still get it on in same *thickness.* Say for instance more pigment,
less gum... Quality of image might suffer, but that depends also on the
paper & the negative, besides which, one person's "quality" is another
person's reject.
> In gum, the process depends on how deep the light has penetrated through the
> emulsion. If it is too little, image will still form but the harden layer is
In combination with other factors, because the light can go through and
through, but if little dichromate is present, can't harden so very
much....
etc.
Judy
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