Chessex Game Mats are manufactured from a specially made vinyl that provides a flat surface for writing and drawing.  The Chessex Game Mats are perfect for marking out maps, building layouts, and dungeon caverns for your next roleplaying campaign.  Using water-soluble overhead-projection pens sold separately (NOT dry erase, grease pencil, or permanent markers), you can write on the vinyl and remove it later with water when the drawing is no longer needed. Reversible Megamat (1 1/2' Sq/Hex)