Solution:

A typewriter ribbon or ink ribbon is an expendable module serving the function of transferring pigment to paper in various devices for impact printing. Such ribbons were part of standard designs for hand- or motor-driven typewriters, teleprinters, stenotype machines, computer-driven printers and many mechanical calculators, before electronic alternatives replaced most of them.

The module consists of a length of a medium, either pigment-impregnated woven ribbon or pigment-coated polymer tape, and a transport mechanism involving two axles. At any given moment, most of the length of the medium is wound as a close-spaced spiral around one axle or the other, tight enough for friction among turns to make it behave mostly like a solid cylinder. Rotation of the axles moves the ribbon or tape after each impact and usually aids in maintaining tension along the roughly straight-line path of the medium between the axles. The module may itself include mechanisms that control the tension in the temporarily unwound portion of the medium