The Cyanotype Chemicals Pack contains 100g Potassium Ferricyanide and 200g Ferric Ammonium Citrate. The chemical names sound alarming but are fairly common place. They have no significant adverse effects on us or the environment. The main iron salt, ferric ammonium citrate, is used as a food additive while the other, potassium ferricyanide, sounds nasty but is only likely to cause problems if mixed with strong acids. Sensible precautions should be taken, wear rubber gloves and safety goggles.
This recipe will make approximately 50 x A4 prints:
- Add 20g Ferric Ammonium Citrate to 100ml water (distilled if possible) and stir until dissolved.
- In a separate container, add 10g Potassium Ferricyanide to 100ml water (distilled if possible) and stir until dissolved.
- Mix equal quantities of each prepared solution in a third container. You can store unused solutions in opaque bottles and away from light, although solutions that have been mixed together will have a limited life.
Instructions and tips:
- The chemicals can stain so protect your work area from splashes. Do not expose the chemical to UV light or sunlight until you are ready to print. Ordinary light bulbs are fine but some fluorescent lighting may also affect your prints.
- Choose your material. Cyanotype prints work well on paper, card, and finely woven fabrics such as cotton and silk. Using a brush, paint the chemicals onto the material, making sure that your work area is dimly lit. Leave the treated material to dry in a dark place such as a cupboard.
- Place a stencil such as a film negative, leaf, feather or cardboard cut-out onto the dry chemical treated material. Place a sheet of glass (if you have one) over the top of the stencil to ensure contact with the surface and expose the sandwich to UV light.
- You can use natural sunlight or a UV lamp and exposure times can vary from a few minutes to several hours, depending on how strong your light source is. The covered areas will turn blue-print blue, and you can check progress by carefully peeling back the stencil and returning it if it is not ready.
- When the print has been exposed, it should be rinsed under running water until all the unexposed chemicals are removed. Wash for at least 5 minutes, until the water runs clear as this will hasten oxidation and bring out the blue colour. Hang the print to dry.
Try our cyanotype blue printing kit to get you started.