Originally Posted by BellaBoo
I marked all over a white cotton tone on tone with every color of the pens I have in the set. I didn't iron it. I washed the fabric in a load of towels and dried it with the towels in the dryer. I put it in the freezer (sub 0) over night. No marks appeared. I am sure the ink washed out.
White tone-on-tone fabric is produced using a form of acrylic fabric paint. Sometimes two tones, one whiter than the other, so that the difference in the feel of the painted portions isn't so obvious. That's why WTOT is more difficult for hand quilters to quilt through than other fabrics.
My hunch is that the fabric paint acts as a pretty good resist for the ink in the Frixion pens.