The play had 'cardboard' characters.
Cover the windows with 'cardboard'.
a piece of 'cardboard'
(..) in two days, and it's all your fault! My... My fault? If you hadn't pushed me out of the window in the first place... Oh, yeah? Well, if you hadn't shown up in your stupid little cardboard spaceship and taken away everything that was important to me... Don't talk to me about importance! (..)1995 Toy Story