(1)
provide a barrier to the passage of carbon dioxide,
which is under pressure in the container; (2) be nontoxic,
unreactive with the beverage, and, preferably,
recyclable; (3) be relatively strong and capable of
surviving a drop from a height of several feet when
containing the beverage; (4) be inexpensive, including
the cost to fabricate the final shape; (5) if optically
transparent, retain its optical clarity; and (6) be
capable of being produced in different colors and/or
adorned with decorative labels