I love using unexpected fabrics (not 100% quilting cotton) in my quilts / projects. I almost never will use the light weight rayon type fabrics though. Neck ties are a great "silky" type fabric most have a good weight to them. That old "70's double knit" makes awesome especially backing fabric it wears like iron and will NEVER wear out. Washing at the same temps and conditions you will be washing the quilts in is very important to make sure how it will lauder. I know this is heresy but I really like the poly / cotton blend mens shirts (mens b/c you get bigger sections of fabric then womens, but womens also for some fancy fabric) as much as the 100% cotton men's shirts.