What defines the mezzotint process in printmaking?

The mezzotint process in printmaking is distinguished by the technique of roughening the entire printing plate to create a rich tonal quality. This is achieved through a special tool, known as a "rocker," which is used to create a series of tiny burrs on the surface of the plate. These burrs hold ink, allowing for a smooth gradation of tones, from deep blacks to lighter shades, when pressed onto paper.

This technique allows artists to achieve a wide range of tonal effects that are not possible with other printmaking processes. In contrast, the other options refer to different methods or characteristics of printmaking techniques. For example, the use of inked surfaces is common to many printmaking techniques, including intaglio and relief printing. The use of acid on copper plates pertains more to etching processes, where the acid creates grooves in the metal for ink to settle. Carving away negative spaces is typical in relief printing techniques, where the areas that will not hold ink are removed. Thus, the defining characteristic of mezzotint is indeed the initial roughening of the entire plate, allowing for a unique and rich tonal output.