A batten is a thin strip of solid material (usually wood).

In cabinetry battens may be used to strengthen panels made up of multiple boards, as in a batten door, or to cover joins.

In building construction, battens are fixed at right angles to the trusses or rafters of a roof to provide a fixing point for roofing sheet or roof tiles.

In sailing, battens are long, thin strips (usually fiberglass, or some similar material, nowadays, but historically wooden) used to support the roach of a sail.

In stagecraft, a batten or rail is a long pipe, usually metal, afixed to the celing or fly system in a Theater.

Woodworking