I use the madam sew pens, I am quite sure it’s the same as frixion ones. I don’t iron to disappear the lines. I ALWAYS wash my quilted items when finished quilting and binding because I spray baste. I also put in the dryer for the crinkles. I’ve tested the cold/reappearing thing with putting quilts outside when it’s freezing and putting smaller items in the freezer. So far I haven’t had any issues. Also I don’t pre wash. I iron while I piece, but never after quilting. Hope this helped a someone.
Denise