On Sunday, 16th March 2014, Selby Markham from the Traditional Darkroom Printmakers’ Group (TDPG) led a workshop on the Gum Dichromate process. Eight participants learned how to make prints using artists’ watercolour paper, photo-sensitive potassium dichromate, UV light, and water.
The all-day workshop required some preparation. Selby brought in watercolour paper which he had pre-shrunk and sized with gesso and the participants brought in A4 negatives which we had made digitally on transparencies. Together we applied a mixture of water-colour paint, gum arabic and potassium dichromate to the paper and allowed it to dry.