Abstract: Transparent receptor substrates, well suited for electrostatic reprography, e.g., for the production of overhead transparencies, exhibit excellent transparency, good slip, good adhesion of toner thereto and good electrical conductivity, comprise (i) a transparent composite polyester base(s) having (ii) a toner-receptive primer coating (P) on at least one of the face surfaces thereof, such composite polyester base comprising (a) a thick layer (A) of semicrystalline polyester and (b) a thin layer (B) of an identical or different polyester adhered to at least one of the face surfaces of said thick layer (A), and the at least one primer coating (P) comprising an acrylic polymer having a glass transition temperature ranging from 10.degree. C. to 50.degree. C., a free --COOH carboxylic functional group content less than 50 millimoles per 100 grams of said acrylic polymer and a thickness no greater than 0.3 .mu.m.

Abstract: Polyester-based, biaxially oriented composite films having good transparency and gas-barrier properties, exhibiting excellent resistance to mechanical shock and being easily recyclable, comprise a polyester base film (for example shaped from polyethylene terephthalate) 5 .mu.m to 50 .mu.m in thickness, coated on at least one of its two face surfaces with a layer of polyvinyl alcohol having a number-average degree of polymerization equal to or greater than 350 and a thickness less than or equal to 0.3 .mu.m, the mean roughness Rz of the base film being less than or equal to 0.30 .mu.m on the at least one face surface of the film onto which a polyvinyl alcohol layer is coated and said at least one coated face surface comprising, on average, not more than 20 peaks of a height equal to or greater than 1 micrometer and not more than 150 peaks of a height ranging from 0.4 to 1 micrometer, per square millimeter, and such composite films exhibiting a permeability to oxygen, measured at 23.degree. C.

Abstract: Polyester-based, biaxially oriented composite films having good transparency and gas-barrier properties, exhibiting excellent resistance to mechanical shock and being easily recyclable, comprise a polyester base film (for example shaped from polyethylene terephthalate) 5 .mu.m to 50 .mu.m in thickness, coated on at least one of its two face surfaces with a layer of polyvinyl alcohol having a number-average degree of polymerization equal to or greater than 350 and a thickness less than or equal to 0.3 .mu.m, the mean roughness Rz of the base film being less than or equal to 0.30 .mu.m on the at least one face surface of the film onto which a polyvinyl alcohol layer is coated and said at least one coated face surface comprising, on average, not more than 20 peaks of a height equal to or greater than 1 micrometer and not more than 150 peaks of a height ranging from 0.4 to 1 micrometer, per square millimeter, and such composite films exhibiting a permeability to oxygen, measured at 23.degree. C.