depths may also vary somewhat between manufacturers. Deep: Medium: Shallow: The frame is made of: 1 top bar: It has two ears from which the frame hangs in the hive box. These are the only contact points with the box. Since L. L. Langstroth (around 1851), the middle part of the top bar is thicker, usually twice as thick as the ears (see picture above). It significantly reduces the building of wax over and between the frames. In addition, the frames are also better to grip. It can have a groove on the bottom in which the wax foundation or strips fits or an edge (usually made of wood) on which the bees attach the wax. Horizontal top-bar hives are associated with the use of movable top bars without frames, usually hold in a larger single box. 2 side bars: They are about as thin as the ears and usually have three or four small holes to attach the wax foundation. 1 bottom bar: It is as thin as the side bars and usually has a groove in which the wax foundation sits. The bars may have furniture - hooks or eyes - to allow for the attachment of wires to brace the frame together. Frames can be outfitted with wax foundation, starter strips or left empty for bees to build the entire comb. Other frames Plastic frames: They are injected-moulded out of plastic and come in various colors. They usually come with built in plastic foundation molded as one piece with cells stamped to a specific size. The colors usually are used to distinguish types of frames within a manufacture's product line (example: green for frames with drone size foundation cells). Queen rearing frames: Specialty frames such as cell bar frames are used to raise new queens. The queen cups are attached vertically to bars to encourage bees to build queen cells. Once these cells are capped, the beekeeper moves them each to a queenless colony for adoption. Drone Trap frames: Some beekeepers have designed frames specifically to encourage bees to built drone brood in order cut it out as part of an Integrated Pest Management (IPM) plan in the fight against Varroa destructor. See also Beehive Buckfast bee Charles Dadant Langstroth hive Wax foundation References Beekeeping tools Buildings and structures used to confine animals Ukrainian inventions Beekeeping