Potassium ferricyanide for cyanotype

Potassium ferricyanide is the second chemical in traditional cyanotype. Dissolve this dry chemical separately, then use its stock solution with green ferric ammonium citrate. Together they form the light-sensitive coating for blue contact prints on suitable paper. Choose this product when you want to weigh your own chemicals following a recipe.

Contents and pack sizes

You receive potassium ferricyanide only, in your chosen weight: 100 g, 250 g, 500 g or 1 kg. The iron component, water, bottles, brushes and paper are not included. Choose according to your recipe and printing frequency. A weight of dry chemical does not correspond to a fixed solution volume or print count.

Ferricyanide or ferrocyanide?

Traditional two-part cyanotype uses potassium ferricyanide, K₃[Fe(CN)₆]. Potassium ferrocyanide is a different substance and is not a direct substitute in the same recipe. Check the name when replenishing your existing chemicals.

Dissolving and mixing

1. Weigh potassium ferricyanide according to your complete recipe and dissolve it in its own bottle.
2. Prepare the ferric ammonium citrate solution separately. Keep the two stock solutions apart until you are ready to coat.
3. Mix the specified solution volumes. In recipes using 1:1, this means equal volumes of prepared stock solutions, not equal grams of each dry chemical.
4. Use separate labelled measuring tools and mix only what you need for the current printing session.

For leaves and photographic negatives

Use the combined coating for botanical prints or a negative on transparent film. Make a test strip on your chosen paper first. Paper, coating, contact with the negative and the UV source affect the result. Dry, expose and wash as your recipe instructs; no fixed exposure time suits every setup.

Storage and safety

Keep tightly closed, dry and out of reach of children and pets. Label solutions and protect them from light. Avoid dust and skin or eye contact. Do not mix with acids, as this can release very toxic gases. Do not heat the chemical. Follow the label and safety data sheet for protection and waste disposal.

Second component and equipment

Combine with green ferric ammonium citrate.

Use suitable bottles, an accurate scale, measuring tools and a brush. Browse the cyanotype accessories.

Prefer both components premeasured? The cyanotype refill kit is an alternative to separate raw chemicals.