The present invention provides a heat-sealable polyester composition having an amorphous processing window ranging from a Tg in the range of about 40.degree. C. to about 70.degree. C., to a Tcg in the range of about 70.degree. C. to about 150.degree. C. The composition preferably contains a mixture of poly(ethylene terephthalate) homopolymer or copolymer and poly(trimethylene terephthalate) homopolymer or copolymer, either as a physical blend or as a copolyester oligomer or polymer prepared from the respective monomers. The resulting composition is heat-sealable at low temperatures, retains barrier properties and is non-flavor-scalping.