I used to use thermore also, but, as it's a polyester batting, I found it doesn't shrink - as I prefer my quilted coverings to do - and it holds in body heat making me sweaty at night.
I now prefer Quilters Dream brand 100% cotton Request loft; it's very thin, has good drape and isn't heat-holding.
I've also used flannel, including in some of the Military Barracks Quilt Project quilts we sent overseas. In those I was occasionally hard pressed to tell, after finshing and washing, which ones had the flannel!
Jan in VA