The photochemical cyanotype printing process (from the Greek kyanos which means blue) is one of the oldest photographic processes. It was discovered in 1842 by the English scientist and astronomer Sir John Frederick Herschel. At the time, the deep blue characteristic of the cyanotype made it uncommon, it was then unacceptable to present a landscape or portrait with this technique.
Despite everything, it found its place in technical circles, used for the reproduction, at low cost, of plans and technical drawings for which the color blue had little importance.
The English botanist Anna Atkins, probably the world's first female photographer, used the cyanotype in her work from the mid-19th century.
More recently, the cyanotype has been rediscovered by artistic circles as a technique with an interesting aesthetic.
The process begins with the manufacture of the reagent, a liquid chemistry mixing ferric ammonium citrate and potassium ferricyanide. This chemistry is then applied with a brush to a paper, we then obtain a paper sensitive to light. Once the paper is dry, the negative is affixed to the paper and then exposed under a UV light source. All that remains is to rinse the print with water and let it dry.
180 years after its discovery, the technique remains unchanged but current digital technologies open up new perspectives.
Indeed, the cyanotype is a contact printing technique, there is no enlargement of the negative, the size of the print is therefore identical to that of the negative. Current digital printing technologies make it possible to produce a negative from a digital file and thus offer the possibility of obtaining very large negatives and therefore large prints that would have been unthinkable to produce from negatives. traditional film cameras.