RE: Hardening salted paper and potassium dichromate

From: Fabiano Busdraghi ^lt;[email protected]>
Date: 06/21/05-03:36:42 AM Z
Message-id: <>

hello Don,
thank you so much for your clear answer. I have read it whit care and the
thread too. I have to work during the week, but on saturday I'll try this
method and I will post my results.
thank you

> 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
> 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

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Received on Tue Jun 21 03:37:01 2005

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