I haven't tried this technique yet, but have a wallhanging that would would look good with this effect. It is a preprinted panel.
Question 1) when you make a slit in the back of the sandwich (I assume you do a sandwich the same way you would for non-trapunto), Do you then cover the back with another back to hide the whip-stitching? Or just leave it that way because it's a wallhanging? It seems like it would seem 'unfinished' that way.
Question 2) is there specific "stuffing" that should be used (or avoided)?
Thanks in advantage for your input.