Cyanotype / NiSO4 toning

REF #93

Potassium Ferricyanid K3[Fe(CN)6] sol. 8%

Ferric Ammonium Citrate [NH4]{y}[Fe{x}(C6H4O7)] sol. 20%

Nickel sulfate NiSO4(H2O)6 sol. 2%

1. Make a basic cyanotype (6 min), with a 30+30s rinse, do not dry.
2. NiSO4 bath for 2 min.
3. Wash 3 times for 30 seconds.