You may need a cardboard shield for many reasons, the most likely being for a Halloween costume. Other reasons include impromptu costume parties, plays, skits and parades. A medieval knight, Greek, Spartan or Roman solider costume would benefit greatly from a shield. Though ancient shields, plastic or metal, can be expensive from costume stores, you can make one at home from cardboard and a few other simple materials. Metallic paint effectively hides the texture of the cardboard, and other embellishments gear the shield toward the ancient culture of your choice. You could even paint the shield to reflect an ancient or magical tribe of your own creation. All you need is a little artistic talent and an idea.
Draw a circle about 4 feet across on your sturdy cardboard, and cut it out. Draw two rectangles about 1 foot long by 4 inches wide. Cut them out.
Spray the circle and strips front and back with the metallic spray paint of your choice. Gold or bronze works well for ancient shields while silver or copper is more appropriate for medieval shields. Spray paint your plastic bowl inside and out as well.
Run a bead of hot glue around the lip of your bowl. Place it upside down in the centre of your shield. This creates a buckler look; the protruding circle helped push enemies out of the way. Let the glue dry for at least an hour.
Paint stripes, running figures, your coat of arms or other symbols around the bowl with tempera or acrylic paints. Use thick pigments; black, red, white and blue are the most common, but you can use green, yellow and orange as well. Use purple only if you are dressing as royalty. Allow the paint to dry for an hour.
Fold up about 3 inches off the ends of your cardboard pieces at right angles. Bend the pieces into rainbow shapes so the folded ends are flush against the back of the shield. Tape them securely into place, adding glue for extra stability. Spray paint the tape. This creates arm straps and finishes the shield.