Blister pack is a term for several types of pre-formed plastic packaging used for small consumer goods, foods, and for pharmaceuticals.
The primary component of a blister pack is a cavity or pocket made from a "formable" web, usually a thermoformed plastic. This usually has a backing of paperboard or a "lidding" seal of aluminum foil or plastic. A blister that folds onto itself is often called a Clamshell.