A word of caution when using the FriXion pens ... Though I've had great luck with the iron making all disappear. When the item gets very cold (freezing), like left on the car when transporting the ink reappears. Try it on a small piece and put it in the freezer to see. I'm thinking it would be a bummer if used without this knowledge. I do no know yet what happens if washed first but would use with caution