Batten

A Batten is a pipe hanging over the stage from which lights, Curtains and other types of scenery can be hung. Theaters typically use 1 1/2 inch "Schedule 40" steel pipe. See also "BIP." Battens may be part of a fly system and able to be raised or lowered, or they may be "dead hung" in one place.

A batten can also refer to a piece of wood, typically a 1x4, serving much the same function as above.

Like much of theatrical nomenclature, comes from the seamen's term "Batten down the hatches."