I use the Clover pen whenever I need to mark dark fabric (which seems to be a lot). Always test a scrap first (I can say that as I have not followed my own instructions the first two or three times - LOL). Use a hot iron and steam. Then wash the fabric gently in cold water. Test the hairspray idea. I haven't tried that, but like ShirlinAZ said - it works on permanent marker, and better on ballpoint pen ink.