Kalotipija

Kalotipija is a photographic printing process that produces a cyan-blue image. It is also known as cyanotype. The process involves coating a surface, typically paper or fabric, with a solution of ferric ammonium citrate and potassium ferricyanide. When this coated material is exposed to ultraviolet light, such as sunlight, a chemical reaction occurs, turning the exposed areas a Prussian blue color. Unexposed areas can be washed away with water, leaving the blue image behind.

Developed by Sir John Herschel in 1842, kalotipija was one of the earliest photographic printing methods. Its simplicity and relatively inexpensive materials made it accessible for both scientific and artistic purposes. Botanists used it to create detailed prints of plant specimens, known as photograms, by arranging leaves and flowers on the sensitized paper and exposing it to light. Anna Atkins, a British botanist and illustrator, is particularly noted for her extensive use of the cyanotype process in her book "Photographs of British Algae" published in 1843, which is considered the first book to be illustrated with photographic images.

While its popularity as a primary photographic process waned with the advent of simpler and more versatile methods, kalotipija has seen a resurgence in contemporary art and craft. Artists appreciate its distinct aesthetic, the unpredictable nature of the prints, and its connection to early photographic history. The process is often used for creating artistic prints, fabrics, and experimental photographic works. Its characteristic blue hue is instantly recognizable.