* papier-mache (store-bought or homemade). If you plan to make papier-mache from scratch, you'll need flour and water

* 10 or more pages of standard-size newspaper

* A 10 to 12 inch square of plywood or stiff corrugated cardboard (two pieces of a pizza box glued together will also work)

* Household vinegar

* Baking soda

* Glue

* A science notebook