The next area we will review before moving on to dynamic testing is creep, recovery, and stress relaxation testing. Creep testing is a basic probe of polymer relaxations and a fundamental form of polymer behavior. It has been said that while creep in metals is a failure mode that implies poor design, in polymers it is a fact of life.1 The importance of creep can be seen by the number of courses dedicated to it in mechanical engineering curriculums as well as the collections of data available from technical societies.2