Ultra low haze, co-extruded, thermoplastic polymer film prepared by co-extrusion of a blend of polyethyleneterephthalate with organic and inorganic fillers in at least one skin layer on a virtually particle-free polyethyleneterephthalate core layer; the inorganic fillers are aluminum oxide particles and/or silicon oxide of average particle size of about 0.035 &mgr;m to about 0.3 &mgr;m, and wherein particles of the organic filler have a particle size of less than or equal to about 0.8 &mgr;m and are present in an amount less than about 0.04% by weight, based on the weight of the polyethyleneterephthalate, the skin layer being less than about 3 &mgr;m in thickness.