My mom's cousin taught me to sew she also quilted and her attitude was if it was fabric it could go in a quilt. She combined all kinds of fabrics together in one quilt frequently. My mom has one of her quilts that was of polyester double knit. Although she passed away long before I ever started quilting I keep her in mind when I make things. We need to keep in mind the real tradition in quilting was, use what you have available. We are lucky to be able to get all the beautiful cottons that are out there but our quilts don't have to be made of just cotton fabrics.