Originally Posted by Dolphyngyrl

I did my own test. If you iron them, then launder them, the marks don't return in the cold, but if you just iron them and don't wash them they return in the cold. I bought one to see for myself because I don't always believe everything people tell me. So my suggestion is to buy cheap muslin, buy a few pens and run your own tests. Thats what I did. Made small blocks drew, ironed, placed in freezer, marks came back, re-ironed the marks, placed in washing machine with laundry, placed back in freezer, marks did nor reappear. II suggest doing this test with a small portion of the fabric you intend to use it on before using the pens on the entire project