A blue almost two centuries old

Cyanotype is one of the oldest photographic processes. It was invented in 1842 by the British scientist Sir John Herschel, who was looking for a way to reproduce his notes and diagrams. But it was a botanist, Anna Atkins, who immediately understood its artistic potential: as early as 1843, she used it to document algae and plants, producing what is considered the first book illustrated with photographs in history.

Since then, cyanotype has never really disappeared. It has spanned eras, resisted digital revolutions, and continues to captivate with its simplicity, its poetry, and that very particular, deep, luminous, immediately recognizable Prussian blue.

How does it work?

The process relies on two iron salts: ferric ammonium citrate and potassium ferricyanide. Once mixed and applied to a substrate (paper, fabric, wood…), they become sensitive to UV light.

Elements are then placed on the coated substrate: plants, photographic negatives, translucent objects, even our own body: anything is possible. Everything leaves an imprint. The whole is exposed to sunlight or a UV source for a few minutes. Where the light strikes, the substrate turns blue. Where it is blocked, it remains white.

Then, simply rinse with clear water to reveal the image: the exposed areas fix into that intense blue, characteristic of cyanotype. No darkroom, no dangerous products: just light, water, and time.

It's a living process, never entirely predictable, and that's precisely what makes it so endearing. Slight variations may appear, which is all part of the charm of the process!