An ink ribbon or inked ribbon is an expendable assembly serving the function of transferring pigment to paper in various devices for impact printing. Since such assemblies were first widely used on typewriters, they were often called typewriter ribbons, but ink ribbons were already in use with other printing and marking devices. Ink ribbons are part of standard designs for hand- or motor-driven typewriters, teleprinters, stenotype machines, computer-driven printers, and many mechanical calculators. Thousands of varieties of ink ribbons and ribbon cartridges have been produced, and are available from stationery suppliers.