Map preservation

[BobbyBaconHat]

As a war game newbie I am wondering how: you can get the maps to lay flat when using them, currently they want to raise up around the folds, and two is there a way to help preserve them long term or better protect them while using them?
What do you guys do?

 

[Barthheart]

3mm (1/8") thick plexi-glass. You should be able to get sheets fairly cheaply. Try to find non-glare.
These will keep your maps flat while playing and protect them from sneezes and crumbs.