Other types of blister packs consist of carded packaging where goods such as toys, hardware, and electrical items are contained between a specially made paperboard card and clear pre-formed plastic such as PVC . The consumer can easily examine the product through the transparent plastic. The plastic shell is vacuum-formed around a mold so it can contain the item snugly. The card is brightly colored and designed depending on the item inside, and the PVC is affixed to the card using heat and pressure to activate an adhesive (heat seal coating) on the blister card. The adhesive is strong enough so that the pack may hang on a peg, but weak enough so so that the package can be easily opened. Sometimes with large items the card has a perforated window for access.
A more secure package is known as a clamshell. Typically used for theft -prone items like consumer electronics , it consists of either two pre-formed plastic sheets or one sheet folded over onto itself and fused at the edges. They are usually designed to be difficult to open by hand so as to deter tampering and pilfering. A pair of scissors or a sharp knife is often required to open them. Care must be used to safely open some of these packages, as 6,000 Americans are sent to the emergency room each year by opening them.
