PEN is an industrial polyester plastic interesting for the physics community as a new type of wavelength shifting plastic scintillator. Recently, PEN structures with good radio-purity and attenuation length have been successfully produced using the injection molding technology. This opens the possibility for usage of PEN as optically active structural components in low-background experiments such as the LEGEND-200 experiment. In this contribution the ongoing R\&D on PEN is outlined with focus on the evaluation of the optical properties of PEN.