Blister packs are created by means of a form-fill-seal process at the pharmaceutical company or designated contract packer. A form-fill-seal process means that the blister pack is created from rolls of flat sheet or film, filled with the pharmaceutical product and closed (sealed) on the same equipment. Such equipment is called a blisterline.
Blister packs comprise of two principle components : 1) a formed base web creating the cavity inside which the product fits and 2) the lidding foil for dispensing the product out of the pack. There are 2 types of forming the cavity into a base web sheet: thermoforming and cold forming.
Other types of blister packs consist of carded packaging where goods such as toys, hardware, and electrical items are contained in between a specially made paperboard and clear pre-formed plastic such as PVC. The PVC, transparent so the item can be seen and examined easily, is vacuum-formed around a mold so it can contain the item snugly, and have room to be opened upon purchase. The card is brightly coloured 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 that this way one can tear open the joint and access the item. Sometimes with large items the card has a perforated window for access.
A more secure package called a clamshell. This is used for theft-prone items like consumer electronics and consists of two pre-formed plastic sheets mated together or one sheet folded over onto itself and sealed together at the edges. These are often intentionally very hard to open by hand, to deter tampering and pilfering. A pair of scissors or even a sharp knife is often required to open them. Care must be used to safely open some of these packages.