I've used a 50/50 bamboo/cotton wadding (made by Sew Simple, I suspect this is only available in the UK under this name, but it's come from the US originally) which I like, it's very soft and the finished quilt has a nice drape. I didn't pre-wash it, though the instructions suggested I should. I'll expect some shrinkage off the cotton part of it when I do wash it. It's a sample quilt and I'm doing this as an experiment, but I don't want to wash it until after an exhibition in June (at The Bramble Patch), just in case it all goes bad
. I sandwiched the quilt using my beloved 505 spray adhesive, quick and easy and no problems with fabric creep or puckering.