an improved heat sealable , peelable seal package structure having walls defined by sheet members and having a region where a first wall portion overlaps upon a second wall portion . the overlapping portions are heat sealable together but are thereafter separatable by peeling . the surface of such first wall portion is comprised of an ethylene acid copolymer , preferably of the ionomer type , and the surface of such second wall portion is comprised of a polyblend of polyethylene and ethylene vinyl acetate copolymer .