From: Sandy King (email@example.com)
Date: 04/28/03-09:46:47 PM Z
I think there is about as much contrast control with kallitype as
with Pt/Pd. Up to this point I have primarily used small additions of
potassium dichromate directly to the sensitizer to control contrast,
and this worked very effectively without any apparent increase in
grain until I reached the equivalent of about 20ml of a 4% potassium
dichromate solution per liter of developer. More than that amount and
printing speed dropped a lot, and grain increased significantly. With
the potassium dichroamte the limits appear to be a DR of about 2.4
down to about 1.2 with no loss of image quality.
I have also been experimenting with the Na2 metal salt and early
tests suggests that it is effective in kallitype as in Pt/Pd for
So in answer to your question, it appears to me that the practical
limits of kallitype parallel roughly those of Pt/Pd.
>One thought occurred to me as this comparison of the two processes
>has unfolded. Does Kallitype offer the same wide range in contrast
>control that is now available in pt/pd printing with the Na2 metal
>salt (without image degradation) ?
>How do you control contrast of the print in your working
>methodology, and what sort of range do you have? In the tests I have
>run, the pd process can now handle a negative density range of
>anywhere from 0.9 to 2.1 with very little image quality problems at
>the lower end of that range.
>Just curious what the practical working limits might be in kallitype.
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