I have read about the grid interfacing in my book "Fast Forward Your Quilts" but have never tried it. It is supposed to use MUCH less thread.
I don't know if my brain could adjust to laying the quilt out upside down and remembering to sew seams in opposite directions every time. But they sure are pretty.
The burgundy one with hollyhocks looks like a postage stamp quilt with applique.
Thanks for sharing!