These tiles are very easy to work with; they're very lightweight, cut easily and take paint very well.  I know most people put them on their ceilings, but I thought I'd try gluing them onto an outside door's panels and gave them three coats of semi-gloss exterior paint.  The end result is that you cannot tell that these are polystyrene--it looks like the door was "carved" that way.  The result is a 5-Star recommendation.