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Showing posts from August, 2011

Van Dyke Prints: An Overview

For a little background to these overviews, see here.

History: Introduced in 1889 by Arndt and Troos, the Van Dyke print is part of a group of iron based processes which draw on Sir John Herschel's work on the Argentotype silver-iron process developed in 1842.

Negatives: A density range of about 1.5 is suitable.

Sensitizer: Part A: 9gms ferric ammonium citrate (green) + 35ml water
Part B: 1.5gms of tartaric acid + 35ml water
Part C: 12gms silver nitrate + 35ml water
In moderate light mix A, B and C (in that order) and age for a few days before use. The solution keeps well for about a year if kept in a cool, dark place. At times, owing to trace chemicals in various supplies of ferric ammonium citrate, the sensitizer may develop a muddy precipitate after about 2/3 of solution C is mixed. This can be allowed to settle and the clear sensitizer on top used, or adding about 2.5 gms more of tartaric acid can also dissolve the precipitate. The additional tartaric acid results in a fainter o…