S.L.
depending upon your environmental views wood can be considered a bad choice - but in my opinion plastic and particle board are worse as they can gas off toxins into YOUR environment - my choice would be real wood - it can be stained or painted and it will hold up better than imitation wood (plastic or paper-covered particle board) - shutters (no matter what they are made of) aren't the greatest insulation barrier but they are better than mini-blinds or curtains (except heavy double-layered ones)and they are much prettier than either of those