Green ferric ammonium citrate for cyanotype

Green ferric ammonium citrate is the light-sensitive iron component in traditional cyanotype. This dry chemical lets you weigh out and prepare your own stock solution. Used with potassium ferricyanide, it produces blue contact prints from leaves, objects or photographic negatives.

What is included?

One separate chemical in your selected weight: 100 g, 250 g, 500 g, 1 kg or 25 kg. Potassium ferricyanide, bottles, brushes and paper are not included. The weight is the quantity of dry chemical, not the volume of a ready-to-use solution.

Choosing a pack size

Use the stock-solution quantity in your recipe and how often you print to choose a weight. A smaller pack is useful when trying a new workflow; larger weights suit repeated use. Print yield depends on the recipe, sheet size, paper absorbency and coating method.

Preparing your solution

1. Weigh each chemical separately using one complete cyanotype recipe.
2. Dissolve the chemicals in separate bottles and bring each solution to the final volume specified in the recipe.
3. Only combine the specified volumes of stock solutions just before coating. Where the recipe says 1:1, this means equal volumes of prepared solution, not equal weights of dry chemical.
4. Use separately labelled measuring tools to avoid contaminating your stock bottles. Mix only what you need for the printing session.

Test paper and exposure

Start with a small test on paper that can withstand coating and washing. Dry the coating away from direct sunlight, expose with a negative or object and wash as your recipe instructs. Use a test strip to determine exposure; no single time suits every paper and UV source.

Storage and careful handling

Keep the dry chemical tightly closed, dry and out of reach of children and pets. Clearly label solutions and protect them from light. Avoid dust and contact with skin and eyes. Follow the label and safety data sheet for protective equipment and waste disposal.

Other materials you need

The second component is potassium ferricyanide.

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

Prefer premeasured components? Choose the cyanotype refill kit as an alternative to separate raw chemicals.