I just took a box that was loaded down with fabric not too long ago, I haven't had much of a chance of going through it, other than look to see what patterns there are and what kind of fabric. I got it from a son whose mother quilted for years but recently had a severe stroke and she asked him to take the box and either give it to someone or throw it in the trash. Some of it seems to be poly-cotton, but she is what I call an 'over-starcher quilter', meaning everything is so stiff that I'm actually afraid to fold any of it or it might snap. So I'm going to have to soak the entire box of fabric in hot water to get all the starch off and then assess if any of it is useable for quilting.
I never say no to free fabric. The way I see it, I'm potentially saving someone else from getting ahold of fabric that might not be quilt quality, and if they're new to quilting, it could spell disaster for them.