Have never used or purchased these pens. I sure won't now. I do needleturn applique.

I only used them once . Yes they ironed out & washed out but once my quilt cooled either way here came the marks , never again

useful information. Thanks for posting

Interesting information - thank you for posting.

Thank you so much for your "homework" on Frixion pens. According to some quilt teachers on You Tube, the Frixion pens are the best thing ever. I have purchased a couple Frixion pens in different colors, so now I'm not sure if I will use them on my fabric in the future for marking lines. I will be careful how I use them in the future and I thank you for your research and sharing it on QB. Happy quilting.

I only use them on the wrong side of the fabric for marking lines for HST or other stitching. If the ghost marks would show up then they are not visible. I would not take the chance of using them on the right side to mark quilting lines, too risky.