Cyanotype photography or "blue print" was discovered in 1842 by English scientist John Herschel. It is a hand-printed photographic technique, known for producing prussian blue prints on a wide range of materials, including paper, fabric and glass.

Cyanotype solution is made using two chemicals - ammonium ferric citrate and potassium ferricyanide. Once mixed, the solution is applied to the surface of the paper and left to dry. This light-sensitive carrier can then have photo negatives of any size, or even objects placed upon it. Once exposed to natural light or a UV unit, the chemical composition changes. When developed in water, the unexposed iron compounds are washed away from the photographs, while the newly-formed water insoluble iron ferricyanide, with its characteristic blue colour, remains.

Above, fine art student Leah Coxon develops her cyanotypes in water. Leah used her own photographs, drawings and objects during the development process.

Like in most  photography, cyanotypes require a photo negative in order to create an image that is the right way round. Printing using a photo positive will create a negative image, as shown above left, and can be used to create unique effects. These are two versions of the same photograph, taken of a felt doll made by artist EC Davies.

Objects can be used in the cyanotype process to create 'photograms'. Opaque objects placed on the cyanotype paperwill produce a white negative shape, where the light has been blocked. Transparent object can give interesting results, like with the disposable glove and pint glass prints shown here.

Artist and Newcastle University Fine Art graudate Ben Applegarth, pictured here, used prisms as a creative way to make photograms. 

Ben made use of interesting shadows produced by the nature of the prisms, while playing with angled light sources. Due to the hand made nature of cyanotypes, no one print is the same, it can be an unpredictable yet beautiful form of original printmaking.