Polymer insulators on transmission lines offer a lightweight, flexible, and vandal-damage-resistant alternative to porcelain and glass insulators. Although many of the early design challenges have been addressed by manufacturers, utilities still need to understand how to select, apply, and inspect these components to achieve the expected design life. Studying the long-term performance and developing short-term tests can help utilities gain knowledge to confidently specify and apply polymer insulators. This can help utilities minimize the mechanical and electrical stress on the insulators in their designs while selecting components capable of meeting the long-term performance requirements.