Abstract: A thermoplastic polyester film including a virtually particle free polyethyleneterephthalate core layer and a skin layer comprising inorganic and organic fillers disposed on the core layer. The inorganic fillers may include aluminum oxide particles, silicon dioxide, zirconium oxide, titanium dioxide, tin oxide, calcium carbonate, barium sulfate, calcium phosphate, zeolite, hydroxy apatite, aluminum silicate and mixtures thereof. The inorganic fillers may have a particle size of from 0.01 ?m to 0.60 ?m. The organic filler particles may have an average particle size of less than or equal to 1 ?m and may be present in an amount of less than 0.1% by weight, based on the weight of the polyethyleneterephthalate. The skin layer may have a thickness of less than 7 ?m.