Throwing off the hump is a wheel-throwing variant in which several small pieces are thrown one after another from a single large mound ("hump") of clay centered on the wheel, rather than centering a separate, individually sized lump for each piece. It is the standard approach for producing a run of small, similarly sized pieces, such as cups or small bowls, quickly.
A large mass of clay, generally several times the size any single piece will need, is centered on the wheel as a whole. Rather than centering it into a flat dome, the hump is usually pulled up into a tall cone, tapering toward the top; a cone stays stable and stays centered as material is repeatedly opened and removed from just its uppermost point, in a way a flatter, wider mound would not. Only the very top of the cone is opened, shaped, and pulled into a small piece, leaving the bulk of the hump beneath it still centered and undisturbed. Once the piece is finished, it is cut free from the hump with a wire at its base, without having to remove and recenter the remaining clay, and the top of the hump is re-centered into a fresh point for the next piece. The cycle repeats until the hump is used up or too small to work further; a hump is often started at somewhere around 25 pounds of clay to allow enough pieces from one centering to make the technique worth the setup.
Throwing off the hump trades a small amount of speed on any single piece, since only the top portion is actually being centered and shaped at once, for a significant speed gain across a whole batch, since centering a fresh lump for every individual piece is one of the slower parts of throwing. It particularly suits small forms where hand access to the hump beneath the piece being thrown is not too cramped; very large pieces are generally centered and thrown individually instead. Each piece cut from the hump needs its base cleaned up separately, usually by trimming once leather-hard, since the wire-cut base is rarely left as the finished surface.