I've had success with the erasable pen. It doesn't rub off, but has ironed off of the fabric. I think it's called FriXion. I've only used the black, but recently purchased the set of colored pens. I stopped in a shop where the owner uses only these pens and she does heirloom projects. She's never had a problem. Some of her quilts were whole cloth with exquisite details - just beautiful.