In response to David's post of 5/24, in all my testing of papers with
palladium the maximum density on anywhere on any of my step tablet prints was
1.45 in the margin on double-coated Buxton. Margin readings were usually a
bit higher than step 1 even when steps 1 and 2 were the same - i.e. maximum
image density. The highest step 1 Dmax was 1.41 on Masa (screen or rough
side).
Most of the papers tested showed separation in 20 if not all 21 steps. The
few which did not could be said to have inherently higher contrast, at least
under the conditions in which the tests were conducted.
Regarding the usefulness of densitometer data, I must admit to being wary of
the use of REFLECTION densities to compare DIFFERENT papers. There are simply
too many visual and tactile qualities that can't be quantified. However, for
evaluating the effects on any one paper of a myriad of possible variations in
contrast, curve shape, printing speed, etc that result from additives such as
potassium chlorate, hydrogen peroxide, and sodium dichromate, or from
changing the ratio of palladium to platinum, or the use of different
developers, or the effects of humidification on density, etc etc,
I think it can be useful.
On another note, I found a copy of Silvie Turner's excellent book "Which
Paper?" that was mentioned recently by Terry King. I think, however, that the
brief section on papers for platinum/palladium printing is for the most part
wrong. While she admits that "it is not easy to recommend a paper for this
process", of the 9 papers listed by name only Fabriano 5 (Classico on this
side of the pond) performed well in my tests. Of the others Rives BFK, Rives
de Lin (Moulin du Gue), Arches Aquarelle, and Strathmore Bristol fared rather
poorly. Saunders Waterford has potential. Rising Stonehenge I did not test
but had tried a couple years ago with lackluster results. Canson Opalux is
one I'm not familiar with. And finally, ANW Opaline may be the "Swiss Opaline
Parchment" that Kerik had mentioned a while back and which seems to work
quite well. I printed a step tablet and 2 real negatives on it just before
putting my darkroom into storage for a while 2 months ago and they were all
very beautiful.
Apologies if I have rambled on too much here.
Happy printing to all,
Keith