Running a nickel over them works pretty good. There is another way, I just can't think of it right now.
These are links to the older posts that I could find.
I hope one of the methods works well for you.
Never tried an eraser, but I do use a plastic kitchen scrubber and it works really well...
I did see one on Pinterest. but the links below are just as good.
Thanks for asking that question. It made me start a search on the internet and while there I also found how to fix a warped cutting mat. I added the link to the clean up and now I am going to see if I can straighten out the mat of my friend that was left in the sun upright.
I got it fixed and it was one of those turntable kinds. Left it out in the sun today (104 degrees). After it was nice and hot, placed a board on it and weight it down with a full watering can. Flat as a pancake now
i once found a rare Frank Sinatra record(vinyl) all warped. Got it for $10 cents. Placed it in a warm oven, put it between 2 sheets of wax paper then weighed it down witha stack of books. a few months later it was flat. Still playing it.
I saw a link to it on DBS