The invention provides ultraviolet light absorber suitable for use as an additive in polymers, comprising particles of inorganic oxide having UV light-absorbing compound on their surface, wherein said UV light-absorbing compound is chemically bonded, either to a spacer provided on the surface of said particle, or directly to the surface of the particle. Process for preparing the additive absorber and a thermoplastic polymer (e.g., a film) comprising the absorber additive are also provided.