Clay,
I think your point is interesting. I have heard the terms "solarization",
"reversal", "silvering out", "bronzing" used for, I think, the same issue.
Someone please correct me if these terms are not synonomous.
I was having some problem with this issue with pure Palladium. I was trying
to print as long a tonal range as I could get with it—thus using small
amounts of Na2. I noticed the reversal effect in the margins, where no Pictorico
or image was masking the thinner brush strokes. Later, when I learned more
about the great importance of humidity (thanks mostly to meeting Carl Weese and
visiting his home in CT), the problem went away after purchasing a 3,000
gallon/minute industrial humidifier.... well maybe not that big...I also would lay
the paper on top of the humidifier for about 20 minutes prior to coating to
let it "soak up" a bit. When it started to go limp, it seemed ready....unlike
other aspects of life. I also cut down on my drying time after coating.
These all seemed to help... but then again, it could have been that I was
wearing my lucky undershorts.
Mark Nelson
In a message dated 1/8/04 3:00:04 PM, wcharmon@wt.net writes:
> May I throw out the entirely untested theory that perhaps this is less
> related to heat than to the depth of penetration of the sensitizer? In
> fact, I HAVE had silvering in the shadow areas of VDB prints that have
> not been heat dried, but they were prints from very contrasty negs in
> which the shadow areas received a great deal of exposure. Is it
> possible that heat drying just prevents the sensitizer from soaking
> deeply enough into the paper fibers because it 'locks' it down before
> it has a chance to penetrate into the fibers?
>
> This would make it a similar phenomena in both in cause and prevention
> to the bronzing observed in palladium printing, which I am convinced is
> due to a sensitizer volume that is too small (read thin) and an
> exposure that is too large (which is why it is in the shadowed areas).
>
>
> Clay
>
Received on Thu Jan 8 22:55:23 2004
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