I tried 2 things: I painted onto the stamp blue “Glassline” glass paint ( diluted the paint a bit as it is old and I thought it needed dilution because it had cracked when I used it before). That came out OK. But the stamp design was enormous, and I would really like all the detail of more intricate ones.
I also did one with the Stringer Medium and powdered frit, which also worked, but only on the huge swirl rubber stamp. Wouldn’t get good detail. Maybe I will try stamping with regular ink!