Nice quilt...I just used color catchers on a black, dark blue, light blue quilt. Although I had prewashed all the fabric, the color catcher came out a nice shade of gray. I have a box to use for quilts..I would hate to get to the final stage of quilting and have all the hard work destroyed just by washing. I am under the assumption that you don't have to use them each time you wash the quilt, right?