I love my Frixion pens. I did my own test on a white on white quilt. After I steamed the marks away, I washed it in the washing machine with regular detergent. Then I put the whole quilt in the freezer for a couple of hours. The marks did not come back. So, then the quilt went in the dryer.

thank you for the info

Getting it cold will cause the lines to appear as a white line, they will not come back in their original color. The ink remains will wash out of the fabric, multiple tests have been done,and the ink DOES wash out.

Please use all these disappearing pens with caution. Think of what they might do to your fabric in 50 or more years. I wouldn't use them on anything that I want to last a long time. A fine lead mechanical pencil works and won't alter/rot/reappear.
SandyQuilter

Well I've been thinking about doing some Redwork but now I think you have me convinced! Another thought, if you have central AC and not using a vent, try laying your work in a thin box (like a thin gift box) and laying it over the vent! I keep my potatoes cool in the kitchen like that! Keeps for ever!! Good luck!

Sandy does have a point! Good thought!

I have black and red and use all the time for cutting lines where any marks left end up on inside.

I love these pens and use them all the time. Yes if you put them in the freezer the marks will return.

The marks do come back if you put the fabric in the freezer, but after you wash the item a couple of times the marks will not return. I love the Frixion pens.

I haven't tried the one I purchased, but was thinking that I would probably use it the most when making HST's so it would not affect/effect (can never remember which one to use without the dictionary) the quilt - I would love to use it when doing applique, will have to try it on a block to see what happens before doing a lot of them.