Abstract: In a material web (1) comprising at least two foils (14, 15) arranged one on top of the other, the foil (15) forming the outside of a packaging container (11) has slit-like openings (17) worked into it at distances from one another, and the foil (14) carrying the outer foil (15) is manufactured from a material that is elastically deformable approximately at right angles to the openings (17). This embodiment makes it possible for the material web formed by the foils (14, 15) to be used in packagings for foodstuffs from within which a resulting excess pressure has to be dissipated in a controlled manner. The openings (17) namely increase in size according to the internal pressure and pore-like openings form in the packaging (11) and in the inner foil (14), with the effect that the excess pressure can be dissipated automatically. As a result, the eventuality of the packaging container (11) bursting during Pasteurization of a foodstuff (20) contained inside it is practically excluded.