Jeffrey D. Mathias (email@example.com)
Fri, 23 Jul 1999 01:02:35 -0400
I did some preliminary Pt/Pd printing on the paper samples offered by
Helcio Magalhaes at APIS '99. This was paper hand made by Helcio from
native Brazil plant material.
The following is what I did:
Pt/Pd process using FO sensitizer.
4x5 negative of Helcio at APIS.
One print on screen side of paper, one print on nap side.
One print on Crane's Parchment for reference.
Exposed for the same time with UV lamps.
developed with Potassium Oxalate
Cleared with H3PO4 (85% reagent grade 2 oz per gallon) and other agents
The following is what I found:
H. paper should have about one and a half times the chemistry as
The H. paper is sized well (excellent) and is easy to coat.
H. paper demonstrated very good wet strength and abrasion resistance.
H. paper floats; this must be considered while processing. If left in a
tray, it should be placed face down (watch for air bubbles) (It will not
scratch on the bottom as it floats). A lid is necessary if placed
vertical in a print washer.
H. paper is a touch, slightly slower than Crane's.
Papers have about the same contrast.
H. paper gives a soft effect (such as a soft focus lens would).
H. paper did not clear completely after one hour in H3PO4 plus time in
Potassium Metabisulphate and time in Sodium Sulfite and time in Hypo
remover. These are the only clearing agents I tried at this time.
Others may do the job??? For this paper to be usable for Pt/Pd, a
clearing scenario has yet to be found. The screen side seemed to clear
better than the nap side, but not completely.
On the screen side, much texture is seen in the print. The screen
pattern shows as not only a relief, but as density differences following
the screen pattern.
On the nap side, the texture is subdued and the image is a bit softer.
The nap side is a bit warmer than the screen side. The screen side gave
a warm charcoal black color more neutral than the Crane's (dark
values). Hightlights were about the same color.
Both sides produced a full and wide range of tonal values. The nap side
seemed to get muddy in places. Good solid dark areas were formed, but
with not as much substance as Crane's.
IF a clearing scenario can be found, this paper could be used with the
Pt/Pd process contributing some interesting effects. Effects such as
color, softness, texture.
I would rate the screen side better than the nap side.
My own preference would be that the H. paper does not provide enough
detail, otherwise it would be fine (if clearing is achieved).
Helcio, I plan to mail the prints to you.
-- Jeffrey D. Mathias http://home.att.net/~jeffrey.d.mathias/
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