What is Cyanotype & its Care
What is Cyanotype
Cyanotype is an early photographic process discovered by John Herschel in 1842. It is a non-toxic method of printing images on paper, fabrics, or other surfaces, using negatives or silhouettes of objects. For my work, I am using the latter approach on silk fabric, with seaweed foraged from Sandycove, Dublin.
While the two iron salts used in Cyanotype have scary names, they are considered safe to use. The process uses just two main ingredients — Ferric ammonium citrate and Potassium ferricyanide. When mixed with water and then combined, they create a light-sensitive solution. Once exposed to sunlight or UV light, a bit of magic happens: the chemistry transforms, and the image slowly develops into deep Prussian blue.
Care of Cyanotype Textiles
Like the felted hats I create, Cyanotype Textiles require gentle treatment.
- If your item is washable, please hand-wash in cold water with a phosphate-free, pH-neutral mild detergent.
- Do not bleach or use harsh cleaners — they will fade the blue.
- Do not wring; instead, gently press out excess water.
- Air dry in the shade, away from direct sunlight.
- Store away from the sun when not in use to preserve the colour.
Like living creatures, Cyanotypes need oxygen. If the blue appears dull after washing or storage, let the fabric breathe in open air, and the colour will revive naturally.