Bohin mechanical Grey chalk refill for extra fine marking pencil 91473 Water soluble, can be washed out or erased with any fabric eraser. Extra fine lead for marking on fabrics. Works great! For patchwork, quilting, garment, clothing, sewing. Twist erase, long lasting. Use with Bohin pencil # 91473 Ceramic colored leads, strong and clorants can not penetrate into the fabric.