On Wed, 19 Feb 1997, Terry King wrote:
> Soaking into the paper will tend to reduce the D-max as the paper will get
> between you and the image. The only difference between practical
Some papers increase D-max when they soak up a lot of emulsion, due to
of having more metal. They require more exposure, however, sometimes a lot
more.
> application of the solutions is that the pt/pd solutions are more expensive
> than the others so one tends to be more careful.
In my experience, application method and papers are different,
even if the emulsion is the same consistency, which it may not
be. Silver nitrate is not the same as chloroplatinate, etc. etc.
> >I've noticed in cyanotype, BTW (haven't made these tests in other media),
> >that, as I have mentioned, with some papers double coating increases
> >D-max, with others it decreases, wiping off emulsion.
>
> Double coating or double processing ( doing the whole thing twice) can
> increase the density range in cyanotype prints from weak negatives.
That's a non-sequitur to the point at hand. However, since you bring up
the subject I'll add that I have never seen a successful "double
processing" of cyanotype -- the paper shrinks, so re-register isn't
perfect. And since there are so many ways to get really good d-max the 1st
time around, that does seem like an exercise in futility.
> >I've never seen solarizing in platinum, but I have seen it in cyanotype,
> >where it doesn't at all become paper white, but a lighter blue.
>
> In a cyanotype you expose until all the shadows are solarised. Then you
> know that it is done properly. The solarised parts turn dark blue on
> development.
Again, Terry, you are committing error, or rather a series of errors, in
tones of absolute majesty. Why do you do that? Doesn't your computer
write the words "in my experience"? I'll send you some software.
Meanwhile, please note: for certain papers (as well as certain formulas)
shadows will not be "all solarized." Or rather (in addition?) there are
different kinds of solarizing. In some cases what has been lighter before
development does indeed look "dark blue" after development, but it may or
may not be the darkest blue in the print. There is also an anomaly that
in some cases what is a lighter blue *visually* is actually denser when
viewed by transmitted light. In any event, I assure you that I have tests
in my file (including one by Mike Ware, of holy name) in which the border
of the strip, which had no film over it, and step #1, appear lighter than
step 2.
However, I have let you suck me into another digression. My question to
Dick Sullivan was, had he ever seen solarizing to paper white. And I
gather from his latest mail that he has not. In which case, I believe
things being attributed to solarizing are probably due to something else.
more to follow,
Judy