Oh wow judykay that's so interesting. Do you have any problems with shifting or any other challenges? I'm finding that my top (linen, so pretty tricky anyway) is being pulled away from me, and dragging backwards against the stitching, and the batting is coming towards me. I improved things by removing the Acufeed foot (Janome built-in walking/dual) but the batting still isn't moving along as quickly as the top - I can't get my head round what's going on exactly, it's the opposite of what usually happens with shifting layers!
Rose_P the decision is following the design really - I'm need an extra minimal look with no border, and the pillowcase method is the only way I've seen to get that. Then, because it seemed likely to be really hard to get all three layers smooth enough to machine quilt once I'd turned it, I thought about quilting just the top and the batting first. I'm getting a really nice aesthetic in my tests - I thought it might look very flat without the back to give resistance to the stitches - but I'd like to know what's causing the shifting issue before I embark on a whole one!