If, with a normal exposure for gum printing, but with no pigment in the gum,
which is what I do when making a 'pterotype', I get no perceptible stain after
washing in water for twenty minutes, and also complete clearing of the
dichromate:
1 Why expose for longer which can serve no useful purpose in terms of the image
?
2 Why use a noxious substance to clear the dichromate, which can damage the
paper and has to be cleared itself, when water does the job perfectly adequately
?
As these are rhetorical questions, I do not want to spoil the fun, I do not
expect an answer.
Terry King