This recipe makes approximately 50 8×10 inch prints. The cyanotype is made up of two simple solutions:
1Mixing the chemicals
Dissolve the chemicals in water to make two separate solutions. Add Ammonium ferric citrate to water into one container and Potassium ferricyanide to water in another. Stir with a plastic spoon until the chemicals dissolve. Mix equal quantities of each solution together in a third container. Unused solutions can be stored separately in brown bottles away from light, but will not last very long once they have been mixed. Dispose of any unused chemicals in a sensible and environmentally friendly way!
Your work area
Your floors, carpets, walls, work surfaces, clothes and skin can be stained by the chemicals. Cover all possible areas, use rubber gloves and an apron or an old shirt to work in. If you have the space, choose an area where you can spread out. Ordinary light bulbs or tungsten light is safe to use, but UV light will affect your prints. Some fluorescent lighting may also affect your prints.
2Preparing the canvas
Using a brush, simply paint the chemicals onto the material. Paper, card, textiles or any natural material can be used to print on. Decide how big your print is going to be, and cut your material to size. Make sure your working area is dimly lit, or lit with a low-level tungsten bulb. Once the material is coated, leave it to dry in the dark.
3Printing the cyanotype
Print a cyanotype by placing your negative (to reproduce a photograph) or object (to make a photogram) in contact with your coated paper or fabric. Sandwich it with a piece of glass. Expose the sandwich to UV light. Natural sunlight is the traditional light source, but UV lamps can also be used. A photogram can also be made by placing items on the surface. Plants, decorative items or other objects can be used to create silhouettes or interesting shapes. Exposure times can vary from a few minutes to several hours, depending on how strong your lightsource is or the season where you are printing.
4Processing and drying
When the print has been exposed, process your print by rinsing it in cold water. The wash also removes any unexposed chemicals. Wash for at least 5 minutes, until all chemicals are removed and the water runs clear. Oxidation is also hastened this way – bringing out the blue color. The final print can now be hung to dry and be admired.