IF you are wanting to remove the lines in case you do not stick strickly to the original drawing I would STAY AWAY FROM pens markers and chalk that are "water soluble or disappearing" The reason is because once these inks are heated you can no longer remove them in many cases. HOWEVER!!! There are pins that you IRON away! So I would say find one of these (I got mine at Joann's) that can be ironed away once you get the bias tape the way you want it iron it down and the lines will disappear as your ironing.