Richard,
Only speaking of this effect on Pt/Pd, I have noticed this (bronzing)
effect as well, as you describe (drying chemistry on the surface).
Sometimes the blower will cause the coating to puddle (even slightly)
causing this same effect. This is especially an occurrence at the edge
of the coating. The remedy that has worked every time is to let the
coating dry until all glossiness looks matte and being careful not to
let the coating puddle (sometimes holding the paper vertical and
rotating helps keep moving the chemistry around.) This effect can
appear to be "bronzing", but more often can look weak or blotchy.
Judy Seigel wrote:
> ... As soon as we stopped heat drying, the bronzing ceased. ... Where bronzing would typically appear was in the most heavily
> exposed shadow areas. ...
It seems that Judy's observations would dismiss Carl's mention of
solarization, because the effect was dependent on heat drying. Unless,
the unlikely scenario that, the heat somehow makes the coating more
light sensitive. It is difficult to evaluate without the benefit of
examining the prints. However whenever I have experienced solarization
with PtPd, the darker areas become lighter but they do not appear to be
"bronzing". Judy seems correct with her assessment that:
> But whatever the
> explanation, my experience is that in these respects pl-pd and VDB work
> differently.
Richard Sullivan also wrote:
> I'd usually pick Key West as the opposing climate but right now it seems that they may be enjoying a Santa Fe climate there as well.
>
> ...Running the paper over a electrostatic humidifier for a minute seems to work miracles in platinum printing, and I'd expect the same for the other metal processes ...
>From Tampa, I can assure you that even though the ground here in Florida
is dry and there are many fires, the Humidity (note with a capitol H) is
still higher than the temperature and near 100%. No Santa Fe climate
here. However, a humidifier is an essential tool except for some thin
papers. Humidify enough to take the crinkle out of the sound the paper
makes when bent. I even humidify some papers here in Tampa before
coating. My real problem is then getting them dry enough to expose
well.
-- Jeffrey D. Mathias http://home.att.net/~jeffrey.d.mathias/