Dual state food packaging

A package for selectively permitting gaseous communication with the atmosphere comprising:

• a tray having sidewalls defining a cavity;
• a product to be exposed to varying gaseous conditions contained in said cavity of said tray;
• said tray comprising an outwardly directed flange extending around the perimeter of said tray;
• said flange comprising an inner flange portion adjacent said sidewalls and an outer flange portion that is further away from said sidewalls than said inner flange portion;
• said flange further comprising a depressed portion between said inner and outer flange portions, said depressed portion extending downwardly from and connected to both said inner and outer flange portions to form a depression in said flange, said inner and outer flange portions and said depression extending completely around the perimeter of said tray;
• said package further comprising an upper membrane and a lower membrane;
• said lower membrane being more gas permeable than said upper membrane;
• said lower membrane extending entirely across the cavity of said tray and secured to said inner flange portion completely around its perimeter to enclose said product in said tray cavity;
• said upper membrane, being less gas permeable than said lower membrane, completely coveting said lower membrane but being unsecured to said lower membrane;
• said upper membrane being secured to said outer flange portion to completely seal and enclose the lower membrane and the product in the tray cavity;
• said lower membrane not extending outwardly beyond said depression and onto said outer flange portion;
• and
• said lower membrane being obtained from a larger web of material, and said depression is designed to facilitate the cutting of said lower membrane from said web after said web is placed on said tray during manufacture of said package.