Easily expandable, nontrapping, flexible paper, microwave package

Expandable microwave package for holding a food product for popping, puffing or expanding in a microwave oven comprising, in combination:

• a bag having an interior for holding a charge of food product to be subjected to microwave energy and including a first wall and a second wall, with the first and second walls each formed of a sheet of non-extendable flexible material, with the first and second walls each including an outer periphery portion, with the outer periphery portions of the first and second walls being interconnected at a seal and puckering as the bag expands when the food product pops, puffs or expands when subjected to microwave energy, with the bag further including at least a first extension to the outer periphery portion of the first wall and extending outwardly beyond the seal, with the first extension including at least a first slit formed adjacent to the seal for relieving constraints to puckering.

Expandable microwave package for holding a food product for popping, puffing or expanding in a microwave oven comprising, in combination:

• a bag having an interior for holding a charge of food product to be subjected to microwave energy and having a top wall including a wall portion having an access opening, with the bag further including a closure portion having an outer periphery of a size greater than the access opening, with the bag including a seal between the closure portion and the wall portion around the access opening, with the bag expanding into an expanded condition, wherein the seal is a cold seal formed of natural rubber and isoprene and/or synthetic copolymers and which fails during microwave cooking allowing trapped steam to vent and allowing the bag to be opened to provide access to the popped, puffed or expanded food product through the access opening.