Place a section of newspaper over the window and tape it in place, with the newspaper edges against the window frame. Cover the entire window, making sure the paper goes all the way to the window frame.
Tape the pieces securely together because the newspaper is the pattern for your window covering. Peel the newspapers off the window frame and turn the sticky ends under.
Center your pattern on the cardboard and draw an outline around the pattern. Cut the excess cardboard off with the utility knife or scissors.
Spread out the newspapers and put the cardboard on top, with the interior side facing up. (This step will not be necessary if you use waterproof cowl-board) Shake the black paint can until it's properly mixed.
Holding the can 8 inches away from the cardboard, spray an even coat of black paint over the entire surface. Allow the paint to dry completely.
Turn the cardboard over, shake the second can of paint -- the colored can of paint that matches the building's exterior -- and spray an even coat over the entire outer surface. The painted cardboard surface will look far more professional than unpainted cardboard from the outside looking in.
Position the window covering in the window frame by holding the covering up and pushing straight in. The covering should fit snugly enough that it stays in place.
However, if the cardboard window covering slides out, tape it securely to the window frame with 2-inch strips of tape.
Things You Will Need
- 1 large piece of heavy cardboard or waterproof cowl-board
- Utility knife or heavy duty scissors
- 1 can black spray paint (optional)
- 1 can spray paint matching building exterior
- Turn a plain roller shade into a blackout treatment, using magnetic strips on both the side edges of the window sill and the sides of the blinds.