Abstract: A package made out of a sheet material like paper, cardboard, etc., and with a welded-seam closure in the upper surface, especially a parallelepipedal package for liquid, made out of a material that is a composite of paper and plastic and having folded triangular flaps that can be folded down against the walls. In order to provide a package that is even easier to open and that in particular will be cheaper to manufacture with respect to the costs of materials, at least one side of the welded-seam closure has a thickening that facilitates ripping into it or ripping it out.