Packaging material for cooking food

A package for cooking food in a microwave oven, comprising:

• an expandable first base film and an expandable second base film that are laminated together and that are configured to form the package having an interior for containing and cooking food and an exterior, wherein the package interior and first and second base films expand in response to pressure buildup created by a microwave cooking process;
• and
• a venting system that includes:
• a plurality of up to 300 laser-formed micro-perforations that have a diameter, greater than or equal to a thickness of the first and second base film, of 10 to 450 microns, that are arranged in at least one lane, that are located in proximity to the food, that expand from the diameter an additional range of 1 to 300 microns during the microwave cooking process and that extend from the interior through the package to the exterior so that they are open prior to and during cooking, wherein the number, size, and location of the plurality of up to 300 laser-formed micro-perforations of the venting system regulate the release of pressure buildup from the interior of the package to the exterior during the microwave a cooking process, and
• a slit at a specific position on the expandable first base film, wherein the specific position corresponds to a position of the lamination of the expandable first base film with the expandable second base film.

A package for cooking food in a microwave, comprising:

• an expandable multi-layer polymeric film that is formed by an extrusion process, and that has edges joined together to form an interior volume for holding and cooking food;
• and
• a venting system comprising:
• 10 to 300 laser-formed micro-perforations with a perforation diameter of 10 to 450 microns that are located in proximity to the food and that expand from the diameter an additional range of 1 to 300 microns during cooking to avoid a bursting of the package during a microwave cooking process, wherein the interior volume expands during a cooking process and the venting system regulates the pressure within the interior volume by allowing excess pressure build-up to escape based on the number, size, location and expansion of the micro-perforations to steam cook the food during a microwave cooking process;
• and
• a slit at a specific position on an expandable first base film of the expandable multi-layer polymeric film, wherein the specific position corresponds to a position of a lamination of the expandable first base film of the expandable multi-layer polymeric film with an expandable second base film of the expandable multi-layer polymeric film.