I prewashed once, and never again. The fabric got so wrinkled and ironing was such a pain. Also, the edges were nasty. That said, I have used all sorts of colors, saturation, etc., and have never had a the colors run. As to washing the quilt, I wash in cold water using Tide. Nothing fancy. And I dry it in the dryer. I don't let the quilts sit in a laundry basket, though. That is tempting fate.