Abstract: A composite film structure containing two inorganic layers each being not greater than 600 angstroms in thickness and having an oxygen transmission rate (OTR) not greater than 0.8 cubic centimeters/square meter-day-atmosphere with one of the layers in contact or in substantial contact with a polymeric barrier layer having an oxygen permeability coefficient (OPV) not greater than 1.5 cubic centimeters-25 microns/square meter-day-atm. The composite film structure has an oxygen transmission rate (OTR) of not greater than 0.012 cubic centimeters/square meter-day-atm and can be used in vacuum panel insulation structures.