From: Sandy King (sanking@CLEMSON.EDU)
Date: 10/30/03-09:53:03 AM Z
Philippe,
Before bleaching the palladium toned kallitype had a a blackish-brown
color. Bleaching shifted it *just a bit* more toward the brown.
I used a color densitometer and used the blue mode, both before and
after bleaching, because the blue reading gave the highest density.
Relative humidity in my working environment is about 60% and remains
about the same all year since the climate control is always on.
Sandy
>OK good test. Thanks for sharing the results.
>And what about the difference of colour tone between a palladium
>print and a palladium toned kallitype ?
>Did you check with a color densitometer ?
>May I ask you the Relative Humidity percentage in your darkroom when
>you print kallitypes ?
>Thanks
>Philippe
>
>-----Original Message-----
>From: Sandy King [mailto:sanking@clemson.edu]
>Sent: Thursday, October 30, 2003 05:48
>To: alt-photo-process-l@skyway.usask.ca
>Subject: RE: Test for Silver Metal in Print?
>
>
>OK, I ran the the ferri+bromide bleach test with a palladium toned
>kallitype. For the test I used the Kodak R-14 formula, diluted One
>Part A + 15 Parts B + 150 Parts Water to bleach the 4X5" tests.
>
>The four tests themselves were toned for 10 minutes each with
>different strength toners, ranging from 2.5ml to 10ml of a 20%
>palladium solution per liter of toner. All of the prints were toned
>with 10ml of the working toning solution. As you can see, the print
>with the strongest toner used about 0.1ml of the 20% palladium. By
>contrast I need about 0.5ml of the 20% solution to make a straight
>palladium print.
>
>All of the prints were bleached for 10 minutes each, after I
>determined that this was the time needed to completely bleach out the
>image of an untoned kallitype . The amount of density lost in
>bleaching ranged from a lot for the one toned in the weakest toning
>solution to very little for the one toned in the strongest solution.
>
>Regarding the print that was toned in the strongest toning solution
>(10ml of a 20% palladium solution per liter of toner), the measured
>reflective density before bleaching was 1.42, and after bleaching it
>was 1.36. This means that the palladium in the print, whatever its
>form, was contributing about 96% of the total density of the print
>before bleaching, with 4% coming from the silver. This is actually
>quite a bit higher than I anticipated after hearing of the results of
>Etienne with other processes.
>
>What I gather from this test is that a palladium toned kallitype
>should have great permanence since virtually all of the silver has
>been replaced with palladium. However, since a very small percentage
>of the silver remains in the print I will continue to call my prints
>of this type as palladium toned silver-iron prints, not just
>palladiums, even though for all practical purposes they are *almost*
>that.
>
>Sandy
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