Flask. A metal or wooden frame to contain the mold and the refractory material packed around the mold for making castings. The flask must be sturdy enough to contain the weight of the mold and the molten metal poured in it. The flask has several layers: the top of the flask is the cope; the center, if present, is the cheek; and the bottom, the drag. A double-sided medallic item could be made with the cope and drag only (since medallic items are generally flat). When a single-sided item is cast, the drag alone could be used; this is termed an open mold. Most all foundry casts are made with flasks.