Cupreatype

Cupreatype

REF #2
Ammonium copper citrate (NH₄)₂Cu(C₆H₅O₇)₂ sol. 20%
1
Potassium Ferricyanid K3[Fe(CN)6] sol. 8%
1

Operating procedure

1. Mix equal parts copper citrate and ferricyanide.
2. Spread onto the paper.
3. Leave to dry for 30 minutes.
4. Expose. (10 minutes).
5. Rinse with slightly alkaline water (pH 9) for 1 minute.
6. Rinse with neutral water for 1 minute.

The first rinse in an alkaline environment is important, otherwise a pink haze will form.