Palladium Curve, was Re: For those who are interested in making digital negatives using pigmented inksets

What one finds after doing a lot of experimentation with curves is
that some of the generic ones such as those provided by Fokos and
Burkholder do indeed work quite well. In fact, with the same curve
developed for carbon I can get very nice results in both kallitype
and palladium. However, if the goal is a faithful reproduction of the
tonal values it is really quite important to configure the curve for
the specific process and printer. Mark Nelson's system of digital
negative making, which has not yet been released, is ideal in this
respect, since the method can be applied to any process and any
printer.

And BTW, I just developed a palladium curve for Pictorico and the
Epson 2000P following Mark's system. The curve is based on the
following conditions.

        1.Epson 2000P. For printing grayscale image, use the following
        settings: Mode = Automatic, Ink = color, media = glossy paper
        2.Sensitizer for 8X10 print = 12 drops Ferric oxalate
        plus 12 drops Palladium plus 2 drops of a 2.5% solution of Na2.
        3. Clearprint Vellum, 20lb stock.
        4. Potassium Oxalate 25% at 100 degrees F.

Be happy to send the curve to anyone interested, but bear in mind
that it would not be useful with dye based printers.

Sandy King

>I was reading Sandy King's very informative article "Making Kallitype
>Prints: A Fresh Look at a Beautiful Printing Process" @ Ed Buffaloe's site
>(unblinkingeye.com) and noticed the statement below:
>
>Quotation > "...There is also a good paper on making digital negatives by
>David Fokos on the Bostick and Sullivan website. Unfortunately, Fokos' paper
>is now several years old and has not been updated to reflect the current
>generation of inkjet printers..."
>
>Fokos' paper is indeed old but... FWIW, I got very successful results
>applying his Platinum curve (intented usage: to make imagesetter negatives
>for Platinum process) to my digital negative making workflow (that curve is
>a Godsend - for someone like me; an impatient-step-wedge-reading-incompetent
>person without a densitometer). The digital negatives for Van Dyke
>Brownprints below were made using an Epson 1160 CIS primed with a pigmented
>quadblack inkset consisting of Conetech Selenium Piezotone Gray inks + MIS
>FS / FSN Black ink (old version - not Eboni) on Pictorico OHP using David
>Fokos' Platinum curve (modifying the last point as 255 - 255):
>
>http://www.photo.net/photodb/photo?photo_id=1999496
>
>http://www.photo.net/photodb/photo?photo_id=2012642
>
>(click the "Large" link below the images to see them bigger)
>
>I think they're nice tonally. What do you think? The most important fact is
>that the tonal range and contrast of the prints are as close as possible to
>what I visualized on my computer screen - that's what counts for me. After
>this recent "discovery" I redeveloped an inclination towards digital
>negatives for Van Dyke (because they're much more easy to make - but lith
>negatives still hold the quality advantage).
>
>I will try the curve with Cyanotypes (but decreasing the density by 10% at
>every point; that way the max density in the negative will be exactly the
>same density according my inferior Cyanotype curves).
>
>Regards,
>Loris.
Received on Wed Dec 31 12:51:41 2003