Cupreatype

Cupreatype

REF #55
Ammonium copper citrate (NH₄)₂Cu(C₆H₅O₇)₂ sol. 20%
2
Potassium Ferricyanid K3[Fe(CN)6] sol. 8%
1

Operating procedure

1. Mix copper citrate and ferricyanide in a 2:1 ratio.
2. Add as much water as the ferricyanide solution.
2. Spread onto the paper.
3. Leave to dry for 30 minutes.
4. Expose. (10 minutes)
5. Rinse with neutral water for 1 minute

Water eliminates the need for basic rinsing, improves whites but reduces dark tones