Laen Finehack taught me this and I had an opportunity to use it this morning. If you grab a Sharpie out of your pen can instead of your whiteboard marker, and start drawing on your whiteboard with it, just grab your whiteboard marker and draw over it and it will come off.
How to remove permanent marker from your whiteboard.
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Thanks for tip! I’ve finally been able to remove the permanent marker from an inherited white board.
Carolyn H.