Since the LQS told me not to prewash, I haven't been doing it. My DD washed my GS's quilt with the color catcher and, fortunately, it did not run or bleed. After reading this post, I think I will prewash my mid to dark colors and definitely do the Q-tip test (brilliant!) on all my colors. I do have a couple of questions, though: how do you keep the fabric from fraying and tangling in the washer and, after washing, do you starch your fabric before cutting, since there is no sizing left in it. Also, if you starch, what kind of starch is recommended? Thanks, I'm still learning!