Packaging comprises polymer film (1) with portions of the film (1) sealed together to form an enclosure for the food stuff, said sealed portions being sealed by a film-to-film seal except in a vent region (5) where a lacquer layer (6) is bonded to each portion of film before said portions are sealed together with the lacquer layers cohering, the seal strength of the lacquer-to-lacquer interface (6) being similar to that of the film-to-film interface under predetermined storage conditions, and the seal strength of said lacquer-to-lacquer interface (6) being reduced compared with that of the film-to-film interface at temperatures above those expected under said predetermined storage conditions so that the enclosure is vented to atmosphere by a cohesive peel action in the vent region (5) between said lacquer layers (6).