Abstract: A carton, blank, especially for use for containers for food products is composed to provide maximum safety against leakage from the container, and to safeguard against gas passage through the container wall. For this object the carton blank is built up as a laminate of paperboard (1), and paper (2) of the greaseproof kind, an adhesive layer, such as a polyolefine layer (3) being used, and said basic member (1, 2, 3) is on both sides provided with external layers (4, 5) of polyolefine. The adhesive layers (3, 4, 5) may, additionally, have dye pigments added to provide impermeability to light.