Cerous (III) polymethacrylate (CPMA), prepared by saponifying a commercial polymethyl methacrylate (PLEXIGLAS) and subsequently neutralized with cerous nitrate, were cast into film from its ethyl acetate solution. CPMA films were subjected to intense uv radiation in order to accelerate the solarization, and they were found to be substantially less susceptible to uv induced degradation than the control which was the film cast from polymethacrylic acid (PMA). A set of CPMA coated PLEXIGLAS films were then tested by the same method and the films with coating thickness of 5..mu.. were inhibitory to uv degradation although the surface density of cerous ion was not uniform. A solar simulator has been installed and calibrated, and initial optical and aging measurements have been made on a series of CPMA PLEXIGLASS films. An automated solarization test system is in the process of being installed.