I just finished hand quilting a quilt and had a lot of pencil marks. I used an eraser, but it only erased a few of the marks. I found success using a product called Marking Pencil Removal from Quilter's Rule Int'l. It is a liquid spray. I sprayed it on the mark, let it sit briefly, then scrubbed with a soft bristle toothbrush. I had to repeat two or three times on the most stubborn marks, but when it dried, all the marks were gone. I highly recommend it.