FotoDave@aol.com
Date: 11/12/01-12:07:22 AM Z
In a message dated 11/11/01 1:52:09 AM Eastern Standard Time,
jseigel@panix.com writes:
<< > ..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)... >>
Hi Judy,
I completely agree with what you said above. I wasn't trying to say that the
contrast of a gum print depends *only* on thickness, but in my email I was
discussing the issue of sensitometry, so I just wanted to point out that
sensitivity can be affected by thickness even if the emulsion mix is the
same, and so it is hard to apply the "standard" sensitometry tests even
though gum printing does obey photomechanical laws.
Dave S
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