The clear plastic thermoformed blister is most often combined with a printed card which has a heat-seal coating so the plastic blister can
adhere to the card.  Sometimes in place of the printed card, foil, plastic or laminated materials are bonded to the pre-formed blister. 

If this style of package were tampered with, it would be obvious thus the blister package is a very popular style when a product must remain secure for the end user.  These are commonly used for pharmaceutical products, but many, many general consumer goods use
this economical and effective packaging style. 

Materials
PVC, PETG, and PET are the most commonly used materials.