RE: Hardening salted paper and potassium dichromate

From: Don Bryant ^lt;[email protected]>
Date: 06/20/05-08:35:21 PM Z
Message-id: <E1DkYbl-000430-H2@smtpauth05.mail.atl.earthlink.net>

Fabiano,

> > I don't harden the size for salted paper.
>
> thank you, this is a first answer.
>
> > In my experience, salted paper is the least contrasty of all processes.
> It
> > handles incredibly hard negatives, too hard for any non-alternative
> silver
> > paper. It can find detail in the deepest shadows (through self-masking)
> > without losing the most subtle highlight.
> > I would try to produce a negative that suits the range of salted paper,
> > instead of trying to make your sensitizer suit your negative.
>
> I agree: whit traditional negatives I do it, but with pdn is impossible if
> the contrast is too low, like in the case of salted paper.
> I cite from the book because it explain better than i can do:
> "If the test print of the Color Density Range Palette fails to yield any
> square or swatch printing paper white, then the Exposure Scale of the
> chemistry mix is too long for the Color Density Range Potential of the
> printer's ink set or output device. Should this occur, the Exposure Scale
> of
> the process should be reduced by using a slightly higher contrast mix.
> Reprinting the Color Density Range Palette with this higher contrast mix
> will
> indicate if the change in contrast is enough to provide a few squares of
> paper white with the printed Color Density Range Palette. If not, increase
> the contrast mix a little more."
> using no dichromate it does not work, and for this reason I increased the
> contrast. this work fine, and I'm happy with the result.
> my questions are: have I to harden size for salted paper (you say not) and
> can y use hardener with paper coated with potassium dichromate?
> thank you for your contribution
> ciao
> fabiano

I will pass along to you some information that was posted on APUG.ORG that
outlines a method for making digital negatives for processes that require a
high contrast negative such as Van Dyke Brown and perhaps salted paper.

This method is used with Mark Nelson's PDN system and was created by a
fellow by the name of David Harris. It has been tested by Sandy King and Sam
Wang and seems to work very well.

The following list of steps was posted at

http://www.apug.org/forums/showthread.php?t=10922

Here are the instructions:

1. Set up a new layer above the green color fill layer.
2. Fill the new layer with black.
3. Set blend mode for new layer to multiply.
4. Choose blending options for the new layer and move the white sliders on
the Blend if underlying layer scale, pressing the Alt key to separate the
two white sliders. Move the sliders until about the darkest 20 squares or so
on the tonal palette are visibly darkened - I found this to be 50/175. I
chose 20 squares so that the blend in would be very gradual.
5. Reduce the opacity of the new layer. You will need to do some tests with
your alt process to determine the correct opacity. I found 2% to be right
for palladium toned POP - when printed it produces tone in the 100 square,
but 101 is pure white (I prefer to have a pure white, others might prefer to
have some tone).

Please note that these instructions were intended to be used when printing a
tonal palette which assumes that you have derived your Standard Printing
Time. Instead of using this technique with Mark's Tonal Palette, in your
case you probably want to start with the Color Density Range Palette so you
can determine your Standard Color Density. Of course once the Standard Color
Density is determined you would use the black ink fill layer when printing
the Tonal Palette to derive your Process Adjustment Curve Data.

Using the black ink fill layer does make the process a bit more complicated
but it does work effectively. For Van Dyke Brown prints, I found through
experimentation that the fill layer opacity needed to be set to 31%. Since
salted paper requires even more contrast than VDB prints do you may want to
start with a 50% opacity setting for the fill layer.

I hope this helps you build a better negative without resorting to adding
dichromate to the sensitizer.

Since I don't know which printer you are using your black fill opacity
percentage may be much different from the values listed above. The figures
that are given are for printers using Epson Ultrachrome inks.

Please let us know if this method works for you.

Best,

Don Bryant
Received on Mon Jun 20 20:35:36 2005

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