TECHNOLOGY FOCUS - INDUSTRIAL STANDARDS - Preferred Components: The barrier film has: a falling dart drop impact (Type A) of 200 g or greater (ASTM D-1709) for a 50 mu m thick film material at room temperature and 50% relative humidity; an Elmendorf tear of 400 g or greater (ASTM D-1922) for a 50 mu m thick film material at room temperature and 50% relative humidity; or a notched Izod impact of 1 J/cm or higher at room temperature and 50% relative humidity (ASTM D-256 for rigid materials).    TECHNOLOGY FOCUS - POLYMERS - Preparation: No preparation method is given. Preferred Components: The component (b) further comprises ethylene glycol, a mixture of 1,3-cyclohexanedimethanol and 1,4-cyclohexanedimethanol, and/or 2,2,4,4-15 tetramethyl-1,3-cyclobutanediol. The component (b) comprises 10-90 mol.% of isosorbide, and 10-90 mol.% of ethylene glycol, a mixture of 1,3-cyclohexanedimethanol and 1,4-cyclohexanedimethanol, and/or 2,2,4,4-tetramethyl-1,3-cyclobutanediol. The component (a) comprises 5-95 mol.% of NDCA, and 5-95 mol.% of FDCA. The component (a) comprises 5-95 mol.% 1-10C-alkyl diester of NDCA and/or glycolide, and 5-95 mol.% of 1-10C-alkyl diester of FDCA. The first polymer is the reaction product of NDCA, and/or FDCA. The second polymer is the reaction product of glycolide, 1-10C-alkyl diester of NDCA and/or 1-10C-alkyl diester of FDCA. The other polyester comprises reaction product of (ia) glycolide, and (iia) one or more polyol comprising a mixture of 1,3-cyclohexanedimethanol and 1,4-cyclohexanedimethanol, and/or 2,2,4,4-tetramethyl-1,3-cyclobutanediol. The other polyester comprises aliphatic homopolymer polyglycolide or polyglycolic acid (PGA), polylactide or polylactic acid (PLA), polycaprolactone (PCL), copolymer polyethylene adipate (PEA), polyhydroxyalkanoate (PHA), polyethylene terephthalate (PET), semi-aromatic copolymer PET, polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), and aromatic copolymers from polycondensation of 4-hydroxybenzoic acid and 6-hydroxynaphthalene-2-carboxylic acid. Preferred Composition: The composition comprises two or more polymers. Preferred Method: The method further comprises orienting the film or sheet in the machine and/or cross direction. EXAMPLE - No suitable example given.