A critical property of electrical insulators is the breakdown voltage. When exposed to a high enough voltage, the insulator will be permanently damaged and unable to block significant current flow which can lead to the compromise of important electrical equipment. This becomes a concern for applications like spacecraft missions, high voltage direct current power, and microelectronics, as well as many others. Recent preliminary tests suggested that water vapor on the surface of insulators may increase their breakdown voltage and influence phenomena observed during breakdown testing, such as partial discharges, partial breakdowns, and surface flashovers. In this study, thin film PEEK (polyether ether ketone) was exposed to a humid environment (35% to 60% humidity) for 60 hours. The electrostatic breakdown of these humidified samples was then compared to fully baked PEEK samples to determine the effects of the humidity
