Typically - i don't pre-wash unless it's a color that concerns me (blacks, reds). If I'm gifting a quilt, I wash it before it goes to the new owner. If I'm making a quilt that I think I want to show (sometimes I don't know I want to show it until I'm quilting it) , I don't wash it until after I'm finished showing/entering it unless it's going to a show that the public votes on.