I have been playing with this for a couple of weeks. I ironed it off and mine did not reappear in the freezer. They are also available at office supply stores. On sale at Walgreens and either Staples or Office Depot this week. If it is still available you can get a $1 off coupon on the Pilot website. I haven't marked a whole quilt with it yet ( none ready) but plan to in the future. I will try it on scraps first. I have only tried the black on Amazon there are a lot of colors. Also highlighters. I hope they are as good as they seem to be. One of the reasons I hate to FMQ is I HATE HATE trying to mark it. I have never found any marking tool I like.