Lid for a packaging container comprising an annular member of plastic, having an opening, engagement means adapted to cooperate with complementary engagement means provided on a container. An inner face is oriented toward the container, and an outer face opposite the inner face, and an annular support surface is on one of the inner face and outer face. A panel of plastic and molded separately from the annular member and comprises an inner face oriented toward the container, and an outer face opposite the inner face, one of the inner face and outer face of the panel being positioned on the annular support surface so as to form an overlapping portion to close at least partially the opening of the annular member. A welding joint is formed in the overlapping portion between the panel and the annular support surface to integrally fix the panel to the annular support surface.