Cyanotype Chemistry

Potassium Ferricyanide

Potassium Ferricyanide

Potassium Ferricyanide is a red salt that is used with
Ferric Ammonium Citrate for cyanotype.


 4 oz/113.40 g  (Item CHM0101)
 8 oz/0.23 kg  (Item CHM1101)
 1 lb/0.45 kg  (Item CHM2101) pictured


Ferric Ammonium Citrate

Ferric Ammonium Citrate

Ferric Ammonium Citrate is a light-sensitive iron salt that is used with
Potassium Ferricyanide for cyanotype.



 8 oz/0.23 kg  (Item CHM1102)
 1 lb/0.45 kg  (Item CHM2102) pictured



Any natural surface, including cotton, linen, silk, canvas, wool, paper, wood and leather.

Add approximately 2 tablespoons/40 g of  Potassium Ferricyanide to 1.7 cups/400 ml of water to create Stock Solution A. Add approximately 1/2 cup/100 g of Ferric Ammonium Citrate to 1.7 cups/400 ml of water to create Stock Solution B. Allow to fully dissolve over 24 hours. Stock solutions have long shelf lives and should be stored in a cool, dark place.

Mix Stock Solutions A & B in equal parts to create the cyanotype sensitizer. Mix only the amount you immediately need, as the sensitizer is stable just 2-4 hours. Coat paper or fabric with the sensitizer and allow to dry in the dark. Once dry, make exposures in sunlight (1-30 minutes, depending on conditions) or under a UV light source, placing objects or a film negative on the coated surface to create an image. (Note: over-exposure is generally preferred to under-exposure. The print should look bronze in color after an adequate exposure). Process prints in a tray of cold water. Wash for at least 5 minutes and allow to air dry. During washing and drying, cyanotypes will oxidize to their final, deep blue color. To instantly oxidize the print to its final color, submerge in a dilute bath of hydrogen peroxide after washing, then rinse and dry.

*The chemicals used for cyanotype are inexpensive and go a long way. Despite their perhaps alarming names, both are safe to handle and mix. That said, care should be taken to avoid ingestion, inhalation and contact with skin.

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Also available Cyanotype Set, Cyanotype Pretreated Fabric Sheets and Cyanotype Pretreated Mural Fabric