Try cutting a measured sized square like 5 or 10 inches of the rayon and a 100% cotton fabric, then put them through a washing machine cycle (using a netted laundry bag), and a dryer cycle. When dry, press with an iron and then measure each for comparison of shrinkage. About the same? then go for using it in a quilt. Vastly different? Pass on the quilt idea and make a dress out of it instead.