Thanks for the idea, True4uca, but I can't visualize what you're describing. I'm sure your explanation was perfectly fine. Maybe you will think of the name of the technique, or someone else will.
If this weren't for a child with a fine art degree, I would never be going there. But mothers are mothers, and I really want it to turn out great for her.
hugs,
Charlotte, who will likely regard all future quilts as surprises