In cyanotypes I capture what grows seasonally in my garden. I also collect objects on walks, which I then capture in a cyanotype in sunny weather.
Cyanotype is an old photographic fine art printing process using blue hues. It was developed by the English scientist and astronomer John Herschel in 1842. In the same year Anna Atkins, as the first photographer, used this photochemical technique for the documentation of an algae herbarium.
To produce cyanotypes, ammonium iron(III) citrate and potassium hexacyanidoferrate(III) are brought into solution and applied to paper.
The prepared objects are placed and exposed to the sun for about 5 minutes. The exposure causes the iron compound to become divalent and insoluble in water. The dye “Berlin Blue” is formed.
The development is stopped by water, excess substances are washed out.
