I've used the Crayola washable markers countless times for marking quilting designs. The marks have always disappeared completely when the quilt was washed. I will say that using the markers on brightly-colored batiks doesn't always work -- the batiks are so bright that I often can't see the marks. In those cases, I just have to "wing it." On one of my quilts, I resorted to printing out my quilting designs, pinning the sheets of paper to the quilt sandwich, quilting through the marks, then tearing the paper away. Ya gotta do whatcha gotta do, right?