Cyanotype is a photographic printing process, first discovered by Sir John Herschel in 1842, and originally used to reproduce his own notes. It wasn’t until a few years later, when botanist Anna Atkins used the process to preserve algae specimens for a book she created, that the process became more well known. Then, due to its inexpensive process, in the later 1800s, this process was used to repurpose plans and technical drawings into what we know as blueprints. The process has been used since then as an alternative creative photographic process.
The tell-tale sign of cyanotype prints are the various shades of cyan blue, a result of the combination of two non-toxic chemicals combined, then painted or brushed on material (like paper or fabric), and then exposed to UV light. The layered lighter images on a cyanotype print come from objects (anything from negative photo prints to wildflowers) that are placed on top of the medium to block any sort of UV light. The print or fabric is then washed with water to stop the exposure process, and as it dries, the classic cyan blue emerges.
Cyanotype prints are archival and meant to last for many years. However, they can be susceptible to yellowing or fading if exposed to phosphates or alkaline environments (like washing with detergents or rubbing your hands with natural oil).
- Minimize washing. If you need to, hand wash in cold water only and hang to dry. Use a non-phosphate detergent.
- If your print does fade over time, you can soak the print in a mixed bath of water and diluted hydrogen peroxide, which will bring the color back to its full potential.