I love the Bohin white chalk mechanical pencil. It goes on in a very fine line. There is an eraser which will take it off but more than likely it will be worn off by the time you're finished. I only mark a section of machine quilting as moving the fabric around will eventually rub the markings off. I haven't tried the Fons and Porter ones but given the comments here that will be on my list to try especially for the dark markings. I am satisfied with the Bohin chalk for marking on dark though.