i use chalk too, it brushes off if i don't use chalk i usually just use a pencil. i tried one of the blue water disappearing pens...what a disaster that was...i did something very wrong with that one...the ink disappeared from the quilt top when i finished quilting and spritzed it with water, it soaked into the batting and leeched through the backing...i made an awful mess of it, so i've never been brave enough to try anything besides chalk or pencil. Chalk if i'm marking as i go; pencil if i'm marking ahead of loading and want it to stay on the whole quilt