Cyanotype / Na2S turn

Cyanotype / Na2S turn

REF #50
Potassium Ferricyanid K3[Fe(CN)6] sol. 8%
1
Ferric Ammonium Citrate [NH4]{y}[Fe{x}(C6H4O7)] sol. 20%
1
Sodium sulfide Na2S · 9 H2O sol. 2%
Cuprous chloride CuCl sol. 4%
Ammonia solution NH3·H2O sol. 13%

Operating procedure

Caution: CuCl must be dissolved in ammonia, not water.
Therefore, the safety instructions for ammonia apply.

1. Make a basic cyanotype (5 min), with 2 min rinsing, do not dry.
2. Na2S bath for 30 s -> deep black. (FeS)
3. Rinse for 10 seconds in basic water (pH 9)
4. CuCl bath for 30 seconds
5. Rinse in neutral water for 30 seconds