Cyanotype

There are currently two available formulas to pick from for printing cyanotype. The classic traditional recipe, and the "new" recipe developed by Mike Ware. They both have plusses and minuses and which you like better is a matter of choice. I have typically used the New formula in my own prints as I like it's deep blue shadows and faster exposure times. But you should expirement and find what you like.

Classic Formula

Ingredients:

• 25 grams of Ferric Ammonium Citrate (green)
• 10 grams of Potassium ferricyanide
• 200ml Distilled Water

1. Prepare Ferric Ammonium Citrate a. Weigh 25g of Ferric Ammonium Citrate into a 100ml glass jar b. Add distilled water up to 100ml
2. Prepare Potassium Ferricyanide a. Weigh 10g of Potassium Ferricyanide into a 100ml glass jar b. Add distilled water up to 100ml

New Formula

Summarized from Mike Ware's Cyanoworks

Ingredients:

• 10g Potassium Ferricyanide
• 30g Ammonium Iron(III) Oxalate
• .1g Ammonium Dichromate
• 100ml Distilled Water

1. Prepare Potassium Ferricyanide a. Weigh 10g of Potassium Ferricyanide into a 100ml glass jar b. Add 20ml of distilled water c. Stir until fully disolved.
2. Prepare Ammonium Iron(III) Oxalate a. Weigh 30g of Ammonium Iron(III) Oxalate into a 100ml glass jar b. Add 30ml of distilled water c. Stir until fully disolved d. Add 0.1g of ammonium dichromate
3. Add Potassium Ferricyanide to Ammonium Iron(III) Oxalate a. Stir well b. Set aside to cool and crystalize
4. Separate green crystals from solution a. Filter the solution through a coffee filter into a 100ml glass jar b. The green crystals and be disposed of by rinsing with hot running water
5. Take to working solution a. Prepare a brown glass bottle with label, stopper, etc. a. Add distilled water to take final solution to 100ml b. Transfer to the brown bottle and store in a dark location

Solution should remain good for at least 1 year

Resources

• Wikipedia: Cyanotype
• Cyanotype: The Blueprint in Contemporary Practice
• "New" Cyanotype