PCT No. PCT/AU94/00521 Sec. 371 Date Aug. 19, 1996 Sec. 102(e) Date Aug. 19, 1996 PCT Filed Sep. 2, 1994 PCT Pub. No. WO95/07949 PCT Pub. Date Mar. 23, 1995A controlled permeability film and process for producing same wherein the film includes: a film forming polyolefin polymer; and an inert porous filler in an amount effective to reduce the ratio of the carbon dioxide permeability and water permeability to the oxygen permeability of the film, wherein the filler has a particle size greater than the intrinsic film thickness of the film forming polymer; the controlled permeability film being further modified to reduce the CO2/O2 permeability ratio to approximately 0.5 to 2.0.