Paint and polystyrene

[Anonymous]

I am using polystyrene for my train layout as well as some side projects and was wondering if you needed to seal the styrene before you paint it? I plan on using plain old spray paint. I didnt know of the paint would eat away the styrene or soak in any goofy ways. If you do have to seal it, any cheap ways to do this would be appreciated. thanks

[nbrodar]

Polystyrene foam insulation? Most spray paints will eat it. Plaster or a good coat of latex paint should seal it.
Polystyrene plastic (like Evergreen)? Most spray paints are OK, but it's always a good idea to test first.

Nick