I learned from my neighbor to place the quilt on couple of laundry baskets in the bath tub, backing side up. You can also do this outside. Take the shower hose and spray with water (warm to cool). By doing it on the backing side, you are forcing the chalk outwards the way it came in. She also prewashes and states she never used the yellow again. The problem is with the post washing the chalk and fabric work like a bit of caking anddoesn't want to come out. If it is forced out the way it was applied it just works better than trying to force it through a couple more layers and often those other layers won't allow it to pass through.