The Printing Process
Tri-colour Gum Bichromate Over Palladium
The photographs of An Unexpected Collection and Global Pandemic are printed using a 19th Century technique called tri-colour gum bichromate over palladium. The technique’s timelessness, craftmanship and originality resonates with my approach to fine art photography.
This process produces work that will stand the test of time (this technique is reputed to maintain its quality for more than 500 years). I chose it out of a sense of archival responsibility. The enduring quality of the print ensures they can be passed down to generations to come.
A preshrunk watercolour paper (I used Hahnemühle 100% Cotton Rag® for An Unexpected Collection) is hand-brushed with a specific chemistry of palladium and ferric oxalate and set to dry in low light conditions. Fixing the negative to the dried substrate, it is then exposed the image to UV light in a burner. The metal-halide screen exposure system vacuums the print and negative together to create a very close contact during exposure that is important for highly detailed artwork. The paper is then put into 3 different stop baths of at least 10 minutes each.
This hand-painted application process is then repeated for each pigment layer over the palladium (Yellow, Magenta, then Cyan) and can be repeated a virtually unlimited number of times to create the desired effect. As you might expect with this crafted process, no two images are alike, despite starting with the same negative. Each one-of-a-kind image can take up to 5 days or more to process.
I’ve treasured my opportunities to learn from photographic printmaker Bob Carnie.