U of S | Mailing List Archive | alt-photo-process-l | Re: re-clearing pt/pd

Re: re-clearing pt/pd



Paul
with small 4x5/5x7 prints. Using 1 or 2 drops of 2.5% Na2 would be fitting (or even 4-5 if the neg is really thin).
If you think about it... if you are using a 6 drop ratio (6 drops Ferric Ox & 6drops pd metal for a 4x5) then 1 drop of 2.5% or 5% Na2 is actually a fairly large percentage of the overall drop count.
I'm using 2.2ml of Ferric Ox and 2.2ml of Pd (thats roughly 44drops of each) for a 12x20 area. and with that amount I usually use my 5% Na2 or 10% Na2 and in the range of 2-10 drops. Just to give you a sense of comparison.
You should be able to create and build a curve that will print well with whatever Na2/FO#2 ratio you standardize on.
I know many folks on here do digineg printing. theyll know far more than I.

Matt



On Dec 30, 2008, at 5:41 PM, Paul Viapiano wrote:

Well, I'm not getting grain or any other artifacts with one drop of FO #2 for palladium.

What I am having trouble with is getting a contrasty enough negative when working with digital negs ;-)

I haven't tried NA2 yet, though I have about 5ml of the stuff at 20%. Since I'm making small prints (4x5 and/or 5x7) I'm wondering if I can get by with diluting it to 2.5% and using a drop or two at that strength...

Thanks, Eric...btw, how many drops of H2O2 will a print take before getting weird? (taking into account total drops, print size, etc)

Paul



----- Original Message ----- From: "Eric Neilsen" <ejnphoto@sbcglobal.net>
To: <alt-photo-process-l@usask.ca>
Sent: Tuesday, December 30, 2008 2:15 PM
Subject: RE: re-clearing pt/pd


Paul, If you are asking will potassium chlorate cause grain right away it
may depend on what strength you are using but it happens very fast. Quite a
number of years back, I tested the FO with chlorate against H2O2 as a
contrast agent and the speed at which grain appeared in the print was upon
the first or second drop but only with the chlorate.

Platonic acid or NA2 will not cause it at one or two or a bunch of drops.

Eric Neilsen
4101 Commerce Street, Suite 9
Dallas, TX 75226
214-827-8301

www.ericneilsenphotography.com
SKYPE ejprinter

-----Original Message-----
From: Paul Viapiano [mailto:viapiano@pacbell.net]
Sent: Friday, December 19, 2008 4:13 PM
To: alt-photo-process-l@usask.ca
Subject: Re: re-clearing pt/pd

Hi all...

Thanks for the clearing suggestions...HCA after citric has worked great!

Now, I know that NA2 is the thing for contrast control, and everyone has
warned me off of Solution #2 oFO, but if I only need a drop or two of #2, it

should be OK, right? Without any problems of grain or anything?

(5/1 or 10/2 type of ratio for the FO...)

Paul