Faux rocks are used in many school plays and in theater playhouses. You can make easy faux rocks from cardboard boxes. The edges of the boxes are crushed to create an unusual shape. The box is then covered in papier--maché to create a bumpy, yet uniform appearance to the rock. The papier--maché is spray painted or brushed to make the rock look authentic. Spray paint that looks like granite is available at many local hobby and craft stores.
Close the lid on the cardboard box. Push, punch or step on the corners to crease them into the box. Punch the sides, top and bottom of the box to make indentations.
Mix the papier-maché.
Tear strips of newspaper 1-1/2-by-10-inches long.
Place the deformed paper box on a flat surface. Another option is to place the box on top of a large plastic bag for easy clean-up.
Dip an entire strip of newspaper into the papier-mache. Pull the strip through your thumb and forefinger to remove excess mache. Place the strip on the box in any location. Repeat the process until the box is covered. Cover the box two more times with strips to make a solid base. All this to dry for 24 hours.
Crumple pieces of newspaper into wads about 2-inches in diameter. Shape the wads to look like long fat hot dogs. Dip the entire wad into the papier-mache. Remove them from the papier-mache and place them on the rock to form a bump. Repeat the process for the desired number of bumps and dips on the rock surface.
Immediately dip strips of newspaper into the papier-mache and cover the wads to create a smooth surface. Use as many strips as necessary to hold the wads in place. Make the connection rounded. Do not make angles in the papier-mache strips. Rocks normally do not have angles. Allow the papier-mache to dry for 24 hours.
Spray paint the outside of the rock with spray paint that resembles granite. Repeat the process to get a deeper color. Allow your rock to dry one hour before moving.