Just figured out something.....could be you all know, but I didn't. DH left some sandpaper here in my sewing room. (I have no idea what he was doing). I was looking around trying to find a pencil sharpener for my soapstone marker. Saw the sandpaper and thought "I wonder if that will work". I works BETTER than a pencil sharpener!!! I wrapped the sandpaper around the end of the marker and just rotated and rotated. It took just a coupla turns. Tested it on chalk and it works well with that, too! I can't tell you the grit ---- but it's rougher than nail files. :mrgreen: