The Darkroom Cookbook Forum

Hi folks. Can anyone offer an approximation of how their gum exposure times relate to the exposure times for cyanotype with the same UV source? Same? Half? Double?

Tim, the following response is from Jill Enfield. Jill is one of the leading experts on alt processes and the author of the bestselling book, Jill Enfield’s Guide to Photographic Alternative Processes: Popular Historical and Contemporary Techniques, https://tinyurl.com/y6gceno

Without going into an explanation, Jill was not able to access the forum so she sent her response to me to pass on.

"gum printing exposures are usually about 2 - 5 minutes where as cyanotypes can be 10 - 45 minutes.

This all depends on your chemicals and negatives and paper. but those are good starting points.

"Do a test when you first get started just like you would in a black and white darkroom. For gum, do 1 minute intervals, for cyanotype 5 min intervals."

Thank you very much Mr. Anchell, and please pass my thanks along to Ms. Enfield. I think hers is the only book on alt process that I haven't read yet.

By this metric I'm massively overexposing my gums. Am currently struggling with the gum just dissolving off the paper during a 15 minute face-down soak in still water. I'll do that test strip again. And cross my fingers. And maybe wave a magic chicken bone around. Gum seems to need some magic.

I have often found that magic chicken bones will often do the trick where more efficacious methods fail.

Jill has asked me to recommend Christina Andersons book:

Gum Printing: A Step-by-Step Manual, Highlighting Artists and Their Creative Practice (Contemporary Practices in Alternative Process Photography)
Part of: Contemporary Practices in Alternative Process Photography (11 Books) | by Christina Z Anderson

https://tinyurl.com/yyujrclm

Thanks for the recommendation. I do have that book. It's a great resource. I still make terrible gums. Maybe my magic chicken bone needs a recharge.