This is just the sensitizer from the Cyanotype kit. 50ml. Store away from UV-light.
The Cyanotype Process was developed in 1842 by the astronomer Sir John Herschel, and was the 3rd process to allow creation of stable images - coming after the Dauerrotype and the Talbotype.
Anna Atkins, a British natural scientist, made this technique famou through her books, in which she documented ferns and other plants using the Cyanotype process. Because of this, she qualifies as the first ever female photographer. From an art perspective, this technique was always a bit of an outsider - for many years it did not count as a photographic alternative process at all.
This process is based on iron, not silver. The exposure times are very long, and mus be made with UV light - for this reason the images can NOT be produced using an enlarger.
In the Cyanotype Kit from Fotospeed, an Inkjet Transparency Film is included so that you can create your own digital negatives. Alternatively, you could expose a negative onto a sheet of lith film using an enlarger, which you would then contact print onto a further sheet of lith film to create a large negative.
This film or the digital negative is then laid on a sheet of paper coated with the Cyanotypie sensitizer (ideally weighted with a glass plate or placed in a contact frame) and exposed in the sun. Under cloudy skies, the exposure time is around 15 minutes. In the exposed areas, the iron in the sensizer reacts and creates a Paris Blue color, which is insoluble in water. The unexposed areas remain water soluble and can be washed away under running water.
The resulting image is soft and somewhat dim. The overall effect can be made stronger with a bath in citric acid.