You will get many different answers here to the wash/don't wash topic. I never prewash precuts, and I have made lots of quilts that are beautiful that contain fabrics that were prewashed along with ones that were not. The whole prewashing thing is a personal choice.... Not a hard set rule ( even if some folks think it is a mandatory step) I prewash when a fabric smells funky, feels funky, is soiled/has something that needs to be cleaned, or is a bleeder. That's (my) criteria... Others have their own criteria