A novel lower tool enables a packaging machine having a molding station with a trough to be used to produce skin packaging having a flat base plate. The lower tool includes a body base and a flat upper surface and is arranged in the molding station of the packaging machine such that the flat upper surface of the lower tool covers the trough. The lower tool fits detachably into a lower tool holder of the packaging machine. During the packaging production, the flat upper surface supports the flat base plate of the packaging. Suction applied via a passage through the flat upper surface is used to hold the flat base plate onto the flat upper surface. The lower tool is a means for converting the packaging machine from producing a first type of packaging having a trough-shaped carrier into producing a second type of packaging that has a flat carrier.