I am really interested in this topic. I find that when I use the pens made for quilting on white material.....it is not good. I have marks left on the fabric and washing does not help at all in getting them out. I have been fortunate because it has been only DQ that I have marked so at least I didn't ruin a big quilt. My instructor for our quilt class suggested using crayola washable markers. Now that was a scary thought but she says that it washes right out.