I don't like not using a batting because the thickness of the 3 layers helps the quilting stitches "sink" in and look flawless. going to throw out a "wild" idea--but what about a thin wool bat? Wool breathes--meaning unlike poly, it doesn't trap sweat. And unlike cotton or a cotton/poly blend, wool is very lightweight and drapes wonderfully. Ask at a local quilt shop to see if they have anything quilted with a layer of wool to see the feel of it.