Papers for pt/pd

Keith Schreiber (KEITH@ccp.arizona.edu)
Wed, 20 Dec 1995 19:54:37 -0700 (MST)

Hi folks,
I've just completed some fairly extensive tests of papers for pt/pd
(more specifically for palladium, since that is my personal
preference) and thought some of you might be interested in the
results. Due to the time of year, what with holidays and all, I am
wondering if it might not be better to wait until after the 1st to
really get into it. Any opinions?
So for now I will give just a summary. Altogether 24 papers were
tested with a Stouffer step tablet (21 steps). Those that *passed*
the step wedge test were then printed with a real negative. My main
criteria were smoothness i.e. solid blocks of tone on step wedge test
without "pinholes" or paper fibers that did not hold the coating, and
a full tonal scale with good Dmax (at least 1.2) and clear Dmin. I
don't have a densitometer so at this point I'm guessing on this but
will soon be able to use a friends to run the numbers on these tests.
I'll report on this when it's done. The coating mixture was equal
amounts of ferric oxalate and palladium with 1 drop of hydrogen
peroxide per 2ml of solution. Exposure was for 10 minutes at a
distance of 8 inches using a bank of 10 24 inch AQA fluorescent
bulbs. Developer was potassium oxalate and clearing was in 4%
phosphoric acid (3 trays - 5 minutes each) with a final soak in Kodak
Hypo Clearing Agent.
Those that passed include Cranes Platinotype, Cranes Parchmont,
Arches Platine, Simili Japon (100, 130, & 225 gms), Buxton, Lenox,
Bienfang 360, and Masa.
Those that were marginal include Rising Gallery 100, Coventry Rag,
Wahon, Gampi, and Strathmore Drawing.
The failures include Rives BFK and Moulin du Gue, Arches Watercolor,
Lana Gravure, Twin Rocker Sweet Cream Calligraphy, and Torinoko.

This is getting rather long so enough for now. I will write up this
stuff in greater detail with comments on each paper and try
to figure out a way to make it available to those interested. This
may take a while so for now if there are any questions on specific
papers, please ask.

Keith
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Keith Schreiber
Center for Creative Photography
University of Arizona
Tucson, Arizona 85721
520-621-7968
520-621-9444 FAX
keith@ccp.arizona.edu