I an thinking of putting 1" foam on top of my 1/2" lywood table top shelf railroad.
My local store has polystyrene foam board. Isn’t that the type that beads all over when cut? I sure don’t want any of that stuff.
If it is white, it is probably the beaded foam. Extruded foam is usually pink or blue. Even with the beaded foam, if you use a hot knife foam cutter the beads will be melted into a solid edge.
I have built my entire layout out of beaded and it is fine, almost no beads if you use a hot foam cutter. Even when I couldn’t use one, the beads were not bad and non existent if you ran a vacuum.
I’m just starting my scenery, using a combination of cardboard stripping and foam to construct slopes and hills, which I will cover with plastercloth, Sculptamold and rocks. I’m using 1/2" and 3/4" pink foam that I could find here in central TX, whereas the 2" is little used here in home construction so more challenging to find and/or expensive to buy. I’m using a knife to cut the pink foam pieces and will use that and a Surform tool to shape it additionally before covering it. I’m happy so far. I can’t compare from experience with working with styrofoam, but if the foam of a cheapo cooler, I think I’d prefer what I presume is smoother cutting foam that I’m using.