There are 2 basic kinds of chalk markers. The first kind is designed for quilting cottons and will usually brush off or wipe off with a damp cloth. The second kind is called tailor's chalk, it's designed for marking on wool suits. The wax melts with a hot iron and blends into the wool. Be careful if you get a tailor's chalk and test it out on your quilting cotton first to see if the wax will blend into the fabric. Sometimes it will stain.