>
>The amount Sandy suggested seems to be about twice as much as my
>extrapolated value which could mean 5% increase may be far from
>enough. If I recall correctly Sandy as plenty of experience and I
>would be confident starting with his numbers instead of mine
>(guesstimates).
>
>Regards
>Yves
>
Yves,
I would emphasize that the exact amount of pigment needed is only
critical when the goal is to make tissues that give very high relief
prints. If the goal is to just make carbon prints that have very good
Dmax a considerable excess of pigment does no harm -- you just
compensate for it by adjusting the strength of the dichromate
sensitizer to the contrast of your negative. In development you would
find that a tissue of this type would retain a very large amount of
pigmented gelatin when you strip it from the final paper support.
However, if prints of high relief are desired one must adjust the
amount of pigment to the minimum. The coating must be completely
opaque, but most of the height of the tissue needs to be affected by
UV exposure. In development you would find that a tissue of this type
would retain very, very little pigmented gelatin when you strip it
from the final paper support.
Sandy
Received on Thu Apr 13 09:28:23 2006
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