Artists Tim Simpson and Sarah van Gameren have taken the humble weeds of inner London borough pavements and turned them into art. Plants are pressed, dried and then composed between plates of glass that function like photographic negatives in the Victorian process of cyanotype.
Traditional cyanotyping or blueprinting was introduced in 1843. Any naturally observant material can be coated with a mixture of Potassium ferricyanide and Ferric ammonium citrate (green) mixed with water. The coated material is then allowed to dry in a dark place. Objects or negatives are placed on the material which is then exposed to UV light, such as the sun, a light box or a UV lamp. After exposure the material is processed by simply rinsing it in water. A white print emerges on a blue background.
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