The force, or force per tape width.

In audio, the force on a tape as it is transported through a recorder. A tape wound on a reel with high tension results in a tape pack with a high interwinding stress.

In film, the resistance to linear motion of the film caused by restraining forces such as tension pads, drive sprockets, take up drive motors, spring-loaded guide rails, and the like, built into projectors, cameras and other film handling equipment.