a method of making multilayered hollow plastic containers having improved resistance to permeation by unwanted gases , especially injection blow molded containers having a preformed inner lining which is applied to a core prior to the formation of the composite parison . one layer is a barrier plastic having substantial but incomplete resistance to gas permeation , and another layer contains a getter material capable of binding unwanted gas uniformly dispersed throughout . the resultant improved container is characterized by having improved resistance to gas permeation .