Styrofoam sheets, or extruded polystyrene foam, can be used for home insulation and as packing material for shipping and crafting, among its numerous uses. The Dow Chemical Company invented it in 1941 and owns the brand name Styrofoam.
Styrofoam is made up of about 98 percent air, which fills millions of pockets in the sheet, making it light, buoyant and an excellent insulating material for walls, floors and roofs. Because the air pockets impede the flow of heat, Styrofoam keeps homes warm in the winter and cool in the summer. The sheets may also be used to underlay roads and other structures to protect them from soil movements due to freeze-thaw cycles.
As a packing material, Styrofoam sheets come in 1-inch, 3/4-inch and 2-inch thicknesses to provide cushion and insulation to fragile, valuable or heavy items without increasing the weight and cost of shipping. Florists and crafters use Styrofoam as structural material to make flowers, wall art, Easter eggs, wreaths and collages.