There are many, many types and weights of batting. My preference is cotton, and if you want it light, try the weight made for wall hangings. Ask at your local quilt shop, or at JoAnn's or wherever you buy fabrics. Lots of good info on line, as well. You can do whatever you like, and the quilt police won't come to your door. But a bit of something in between top and backing gives your quilt good shape and dimension.