Our Combat Mats are designed for the serious gamer. They roll up for easy storage and have a wet erase surface for smudge-free use. Unlike most other mats you have seen, ours are two-sided, providing both one inch square and one inch hex grid systems. Perfect for every role-playing game scenario, small, medium, or large. You can write on them using WET ERASE MARKERS only. We have found the Staedtler Lumocolor 315 pens work the best.