It is the objective of this series of articles, beginning in this issue, to review for users the benefits of polymer insulating materials. Material science, design, and processing conditions all influence performance and must be considered. Using silicone as an example, we will discuss performance considerations and present data on performance counter to common industry perceptions. The series goal is to acquaint the user with relevant topics so that more informed decisions can be made in the evaluation, selection, and use of outdoor polymer material insulation. In Part I, a comparison of porcelain and polymer properties is presented, including the relative advantages of each.