I always wash & dry ALL of my fabric before cutting anything out!! I have done this ever since a polyester fabric (that does not shrink - right?!) that I had made a pants suit out of it (back in the 70's). Well, low and behold - the first wash & drying -- it shrunk !!!! And not just a little!!! So, ever since then everything get washed and dried first. It it is wool - then I send it to the dry cleaners 1rst, before cutting. And, the rag quilts will turn out just fine if the fabric is washed and dried first too. That way they won't shrink up.