Not sure if you're hand or machine quilting. I'm a hand quilter and use a #2 mechanical pencil for light fabrics and a Bohin mechanical pencil with white 'lead' for dark fabrics. I generally mark as I go. Have only ever had a problem once with the lead pencil not washing out completely. I've also used the (I think) Clover chalk mechanical pencils in all kinds of colors. Never had an issue with any of them not washing out either.