cyanotypes were invented by John Hershel originally intended to be a way or reproducing drawings known as blueprints.

cyanotypes are made from Potassium ferricyanide and Ferric ammonium citrate are mixed with water separately.

Cyanotype’s uses different iron compounds, which when shown UV light then washed in water then there is a blue images.

Anna Atkins used cyanotypes to publish the first book with illustrated photographs.