The Madeira Magic Marker pen can be used on all different types of fabric and is more accurate, convenient and quicker to apply than marking with pins or thread. The pen has both a fine and thick tip (one on either end) and the ink is purple. The line disappears within a couple of hours, depending on the nature of the fabric. The pen is handy to use and is a useful addition to any sewing kit.as with all markers, test before use.