Back in the world of the non-toxic printmaking, I got some great advice from printmaker and blogger Aine Scannell a few days ago. I've been looking for ways to reproduce aquatint tones on a collagraph plate. I was experimenting with different strengths of acrylic resist mixed with carborundum, but she suggested I use pastel ground. Pastel ground already contains minute particles of grit which will hold a lot of ink when dried on a printing plate. On the following two plates, I used straight pastel ground for one of the figures, and a tiny amount added to water for the background shapes:
Result: a beautiful variation in tonality, pretty similar to an aquatint. Adding some lines scratched into the Lascaux resist in other parts of the plate leads to even more variety and lusciousness of mark making.
I am heading out of Chicago next week to go and teach a monotype class in northern Michigan, so I will mainly be brushing up that technique. But these prints represent another breakthrough for me with collagraph printmaking, one which I will pick up in earnest when I return to my studio after the workshop has ended.