I want to build an outdoor nativity scene - I have the pattern for it -- but I do not know what sort of wood/material to use for it. I need it to be waterproof - easy to cut - some people have suggested plywood - others - core flute - Acoustic Panels Polyester Board - does anyone have any suggestions that may work for an outdoor nativity that sits in the yard for about one month over Xmas then gets packed away. I want to be able to paint it as well so it has to be paintable.