I have the Clover mechanical pencil like thing with colored & white chalk. That worked well and washed out. The Crayola markers I left on a quilt for a year before I quilted and washed it and it all came out. I also used the markers to mark around the templates on a hand pieced table runner that I started when my FIL was in the hospital. Took me about 8 yrs to get back to it. All that was on the back of the pieces, the inside of the quilt but I think it all washed out. I can't see anything. I have even ironed on the markers and it has washed out. The yellow is harder to get out for some reason. I have to wash that twice to get it all out sometimes.