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Sidero-Cupreatype

Sidero-Cupreatype

REF #4
Greyish blue Medium grey White Grey brown Navy blue Grey yellow Grey green Pinkish beige Dark pink
Ammonium copper citrate (NH₄)₂Cu(C₆H₅O₇)₂ sol. 20%
Sodium thiosulfate Na2S2O3 sol. 10%
Cuprous chloride CuCl sol. 4%
Ferric Ammonium Citrate [NH4]{y}[Fe{x}(C6H4O7)] sol. 20%
1
Potassium Ferricyanid K3[Fe(CN)6] sol. 8%
1
365nm

Operating procedure

This is the second way to obtain a sidero-cupreatype:
- Apply an insoluble copper salt to the front side.
- On the back side, make a normal cyanotype (here 6 minutes).

Here, we obtained the insoluble copper salt by mixing copper citrate (2 parts), thiosulphate (1 part), and CuCl complexed in NH3 (1 part), then leaving it to dry.