the present invention is directed to a multilayer film having , as its main component , a hydroxy acid polymer with improved gas barrier and optional heat sealability . the oriented film of predominately hydroxy acid polymer having controlled shrink can be produced by melting and coextruding a hydroxy acid polymer with a much thinner layer of an amorphous aromatic copolyester to form a multilayer film that is quench cooled , then biaxially stretched at a process temperature above the glass transition and below the cold crystallization temperature of the hydroxy acid polymer . a heat - setting treatment with a controlled relaxation of the film above the hydroxy acid polymer glass transition temperature and below its melt temperature may be used to control shrinkage . the films thus obtained are vacuum metallized on the aromatic copolyester surface to produce environmentally friendly packaging from predominately renewable resources having improved gas barrier properties .