Gum bichromates

Sarah van Keuren

A Non-Silver Manual: Gum bichromate

The chapter called “Gum bichromate” of Sarah Van Keuren’s book “A Non-Silver Manual: Cyanotype, Vandyke Brown, Palladium & Gum Bichromate with instructions for making light-resists including pinhole photography”.

The ferric gum process

Ferric gum process – a radically different variation on gum

The ferric gum process is like gum bichromate in some respects but it is also radically different. Sensitiser is brushed onto the paper, the paper is dried and exposed under a suitable image, and only at this point would pigmented gum be brushed onto the exposed paper.