Anyone using ultramarine blue in gum printing notice this, that a sulfur smell is given off when mixing it in the coating solution? I did, thought I was being overly sensitive, but noticed that Sarah Van Keuren and Rudi Dietrich said the same. This doesn't mean it doesn't work--it works fine in gum, but it's just stinky...If ultramarine is sodium aluminum sulfosilicate, is it possible, chemists on the list, that the acidity of the gum would be responsible for releasing this smell? I do have a hyper sensitive nose, I have been told.
PS I am working on the "certain pigments don't work" section...that is fascinating.
Christina Z. Anderson
Photo Option Coordinator
Montana State University
Bozeman, MT 59717