I have nothing against polyester I do make a quilt out of all of one or other fabric no mixing I think when the cotton thing really started was over hand work and the creasing needle turn applique was very difficult with a polyester blend as well has hand quilting more difficult to needle but with all of the machine work nowadays I don't see where it makes a difference I just do not mix the two poly is much stronger hardly ever bleeds or fades with age and I like it for pillow cases does not need the ironing