I haven't personally tried these pens, but I've read quite a few reviews. One problem is that the marks reappear when the quilt gets cold. This has happened when quilts shipped to shows get put in the airline baggage compartment, causing at least one quilt to be rejected at a show. It can also happen if you drive in a cold climate with the quilt in the trunk of the car. Another problem has been that the lines have sometimes not entirely disappeared, especially on batiks. I would personally try another option, rather than tempt fate by using these pens. They weren't made for fabric.