Trial and error triumphed. Putting Vilene stitch and tear behind the cotton lawn did the trick. I think the stitches I chose to use were just too dense for such fine fabric - with this thickish backing it held everything in place. Tearing it away gave minimum distortion, but not enough to worry about. I've looked up stablisers and there is a paper wash away or an iron away. I'd try this in future for heirloom type work. The wedding photo is printed on inkjet fabric, it works great - I can see so many possibilities using this. I need to put some final touches to front and back, then work on assembling the bag - only 8 days to go and it must be finished.