A retail store would be preferred.
Sheets of clear plastic can be purchased in hardware stores, or at plastics stores (look in your yellow pages under Plastics, or go to a Tap Plastics if you have one in your area), or you can even use one from a frame you might have sitting around. To cut it, if necessary, you'll need a special cheap cutter... or if you go to a plastics store, they'll cut it any way you want usually charging by the cut (and you can get more thicknesses, etc.). Diane B.
Depending on the thickness you need Home Depot or Lowes.
