Re: Hardening salted paper and potassium dichromate

From: David & Jan Harris ^lt;[email protected]>
Date: 06/20/05-11:46:15 PM Z
Message-id: <001101c57624$8d55ae30$93bf6951@sotera>

Alternatively for a very low contrast process it is possible to develop an
extended colour density range palette which uses black inks.
----- Original Message -----
From: "Don Bryant" <dstevenbryant@mindspring.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, June 21, 2005 3:35 AM
Subject: RE: Hardening salted paper and potassium dichromate

> 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 23:44:43 2005

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