I made 2 double knit quilts in the 70's, with one more cut and ready to sew, which I plan to do real soon. I backed one with a sheet blanket and one with a poly/coton sheet. The best part of using a quilt of double knit is that they are very warm. They also will out last the backing. I have rebacked one 2 times and the other once. I say go for it.