Go ahead and use the pen but should the quilt be exposed to cold, the marks WILL return and heat will have to be applied to again remove them. (such as shipping a quilt across country - shipping to cold climate - stored in cold area) There is NOTHING that will remove the ink. It becomes transparent with application of heat, but it IS still there. Just a word of caution. I used a Frixion pen to mark a DWR quilt and learned this the hard way. Now when I use this pen (only on a rare occasion), I write theses instructions on the quilt label that I attach to the quilt.