Re: silvery sheen & fisheyes

  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
On Jan 8, 2004, at 2:48 PM, Judy Seigel wrote:

>
> On Thu, 8 Jan 2004, epona wrote:
>
>> hmm. perhaps i should have mentioned this sheen was not visible until
>> the print dried - while wet, it looked pretty darn good. i air-dried
>> it overnight.
>
> The seductiveness of this discussion of the MECHANISM of the
> silvering, or
> plating out is easy for me to resist because it's so far over my head.
> However, I think two points are worth making:
>
> 1. I didn't mean heat drying AFTER printing, I meant heat drying of the
> emulsion before exposing. The fact that the silvering doesn't show up
> until the print is dry (usually) only stands for itself, doesn't tell
> anything about what caused it. Whether the cause is keeping the
> emulsion
> on the surface, or an effect of heat on wet emulsion, or perhaps the
> proximity of electricity molecules -- would have to be proved.
>
> 2. Of literally hundreds of students doing VDB, I never saw the
> silvering-- or plating out -- on a print that hadn't been heat dried.
> Or
> to put it another way, before the penny dropped & I made the
> connection,
> we often had plating out (students are in a big hurry -- hair dryering
> seems to be the norm, reflexive in fact, at school). The patterns of
> the
> silver in the shadows could be quite stunning. Too bad it proved nearly
> impossible to control.
>
> Of course that was VDB. Christina/argyro may have a different
> phenomenon.
>
> Judy
>
Received on Thu Jan 8 14:59:18 2004