Abstract: A container is made out of a flat material like paper, cardboard, etc., especially a parallelopipedal container for liquid made out of a composite of cardboard and plastic. The container has a ridged-seam closure that extends along the upper surface and, continues at each side, along fold-down triangles, which can be applied against the walls of the container, and which are demarcated by scores. The scores slant from the upper edge of the walls to the ridged-seam closure, and at least one of the scores is provided with a tear-out closure, which has material-weakening lines in the area of the wall that constitutes the fold-down triangle which are arrayed in the shape of a U with a basic perforated line that parallels the base line of the ridged-seam closure and with leg-like perforated lines that extend perpendicular to the basic perforated line, which they encounter in the vicinity of the slanting scores.