THERE IS HOPE!! I just posted about the Fons&Porter Mecaanical Pencil, that I love & have used for years.Which just gave me an idea;of how to get these dark, ironed on lines, from a pencil, that I'd just grabbed & used, w/o thinking the other day. I just went in & tried the ERASER,from my Fons&Porter Mechanical Pencil. IT WORKED!!! ENTIRELY ON SOME MARKS. Not entirely,on all marks but it made marks SO MUCH LIGHTER, than they were.I now know that I can get these marks out!!