Preventing boards from warping...

[vikotnik]

This one goes out to the terrain builders among us:

I have gone to great pains and lined 1cm MDF board with styrofoam before applying my terrain mix consisting of white glue, water sand and (unused) cat litter.

A few days later, I noticed that it was warped nonetheless!! :x  :x

How do You prevent the gaming boards from warping after You have applied Your terrain mix?

[Lowtardog]

Weight the boards down if possible, at the corners etc. Or if you can pin them to a work surcafe with bulleting board pins, I have used that before. Mind you suppose it depends on the size of the board as to whether this is practical.

My suggestions relate more to buildings on boards

[white knight]

I've heard the trick is to piant the other side as well (with water even).

[The_Wisecrack]

how about nailing a wooden frame to the back. nothing complicated just some boards going with the  warp to keep it straght.