Cyanotype is one of the earliest photographic processes, developed in 1842 by scientist John Herschel through experiments with light-sensitive iron salts. Shortly after, botanist Anna Atkins adopted the technique to document plant life, producing the first photographically illustrated books in 1843. Her work established cyanotype as both a scientific and artistic medium. For more than a century, the process was also used by architects and engineers to create ‘blueprints’, a term derived from the medium’s signature Prussian blue hue.

Unlike silver-based photography, cyanotype relies on iron salts that react to ultraviolet light and water to form an image. One of its most distinctive applications is the ‘photogram’, in which objects are placed directly onto a coated surface, capturing their silhouettes rather than photographic detail. This direct-impression method has been central to cyanotype since Atkins’ early botanical studies.

The process involves coating natural materials with a UV-sensitive solution, arranging botanical or found objects on the surface, exposing them to sunlight or UV light, and rinsing with water to reveal luminous white forms against deep blue backgrounds. Cyanotypes can be created on a wide range of natural fibers and materials, including cotton, silk, canvas, wood, ceramics, and glass, and can be further transformed through bleaching, toning, or other alterations to produce unique visual effects.

Check out my Cyanotype Pinterest board for a range of different cyanotype images and videos.