Sunday, November 11, 2007
The Gum Bichromate process is a contact printing process, in which a large internegative is made from the original black and white negative. This enlarged internegative is then placed on top of sensitized printmaking paper, in my case Rives BFK, that has been previously coated with mixture of gum arabic, amnomium bichromate and watercolour, which is the emulsion that renders the paper light sensitive. When exposed to natural light,the tones of the internegative are printed onto the paper and the unexposed areas are washed away in development in water. A wide range of colours can be applied in separate layers, and the finished prints are archival and will not fade, and each print is an original. The random brushmarks surrounding the edges of the negative form part of the final image, giving a painterly quality to the finished print.