Building and basing terrain

[Gondorian]

I want to build a series of small pieces of terrain for a little tournament that I'll soon be running. Things such as wrecked vehicles or rocky outcrops capable of holding about one 40K squad in cover.

Two questions are:
What is the best wood to base such pieces with? I want something relatively thin and light but that will not warp.
Is there a way of making polystyrene (typically the stuff used for packaging) more durable? I seem to recall something long ago about painting it with pva glue but I cannot remember the purpose of this or how it effects the polystyrene.

Any help will be greatly appreciated.

[bantha_fodder]

coating it with pva should stop bits flaking off the outside.
it should also protect it from melting- as some paints/glues will dissolve the polystyrene.

[Eldanar]

One way to add to the rigidty of polystyrene would be to coat on a thin layer of sand and glue, about 50/50. When this stuff dries, which might take a day or two, it is as hard as concrete. Make it about 1/8-1/4" thick.

On the flip side, you could just go to a hardware store and buy some pressboard. It is hard as hell to cut (you will need a power saw...a dremmel won't cut it very well), but it is extremely durable and will not warp.

[TCUTTER]

small terrain, you thought of using cork board for basing? i do on all my little pieces and small objectives, its sturdy as hell, as for basing, when youve put the sand on and its dryed wash it with a 50/50 mix of pva and water to seal it, trust me man sand falls off otherwise, foam core is also good for terrain