This dual marking pen has a ball point pen at one end and an eraser at the other, so you can make your mark and immediately erase it. Or, take advantage of the air erasable quality of the fine line pen and let the ink do the work for you. Marking will automatically disappear in 2 to 10 days depending upon the humidity in the air. Always test on a scrap piece of fabric before marking your project . Air Erasable pen features pink ink.