Here is the link to how I made a 12” x 12” encounter placard for underground run ins with bad guys and bad things

http://armoredink.blogspot.com/2010/01/cavern-encounter-placard.html

Object of the board is for very small groups of figures to have something to fight on without having to drag out my 4x6 foot game table for Pulp adventer games and D&D. Probable cost of materials, tile 60cents, foam was left over scrap free, caulking probably couple dollars from what I keep on hand and 10 cents worth of hobby acylic paint from a craft store. Oh and some dabs of hot glue, less than half a stick.