Mezzotint is a printmaking process of the intaglio family, technically a drypoint method. It was the first tonal method to be used, enabling half-tones to be produced without using line- or dot-based techniques like hatching, cross-hatching or stipple. Mezzotint achieves tonality by roughening the plate with thousands of little dots made by a metal tool with small teeth, called a "rocker." In printing, the tiny pits in the plate hold the ink when the face of the plate is wiped clean. A high level of quality and richness in the print can be achieved.

From Wikipedia, the free encyclopedia

Definition: La manière noire ("the dark manner")
The term reveals its meaning. A mezzotint–from the Italian mezzo ("half") and tinta ("tone")–presents halftones. Specifically, in this type of intaglio (nonrelief) print, subtle gradations of light and shade, rather than lines, form the image. (For a complete history of mezzotint, see the link to the National Portrait Gallery Web site below. For a bibliography of sources related to mezzotint, see the link to the Print Council of America Web site below.)

From The Metropolitan Museum of Art

Shepherd piping to a Shepherdess

by Robert Robinson, published by Isaac Beckett
mezzotint, circa 1683-1688

The early history of mezzotint  (National Portrait Gallery, UK)

John Martin: English, 1789-1854

Fall of Babylon from Illustrations from the Bible, 1835
Mezzotint and etching

Mezzotint is an intaglio medium in which the artist begins with a heavily textured plate that prints a solid black. The plate is then selectively scraped and burnished to create smoother areas that will not hold ink, allowing the artist to work progressively from dark to light. For this reason the technique lends itself to images demanding rich black or extensive tonal passages. The process begins by texturing the plate with a tool called a rocker. A rocker resembles a very broad flat chisel with an arced edge. One of the flat faces of the tool his very fine grooves in it so that the sharpened, arced edge is actually made up hundreds of fine points. The rocker is worked across the surface of the plate with a motion something like that applied to a vegetable chopper. As the rocker travels across the plate in horizontal, vertical, and diagonal courses it slowly builds up a texture that will hold enough ink to print a solid black. After the plate has been completely rocked the artist begins to scrape back into the plate to create the lighter passages. This results in the characteristic velvety passages of mezzotint. Often the process of scraping and burnishing the plate reveals the underlying courses of dots that make up the mezzotint tones. In this example this is extremely difficult to discern, but if you examine a detail of the clouds in the upper left hand corner you will see a subtle example of this. In the lower left you can see where Martin has worked back into the plate with traditional etching.

• Ludwig von Siegen– inventor
• Prince Rupert of the Rhine
• Richard Josey(1840–1906), engraver of James McNeill Whistler'sWhistler's Mother.
• M. C. Escher
• Peter Ilsted
• Alexander Hay Ritchie
• T.F. Simon
• Toru Iwaya
• John Sartain
• G. H. Rothe(1935–2007)
• Luke Vehorn
• Francisco Souto
• Carol Wax
• Robert Kipniss
• Julie Niskanen

(from Wikipedia)

The printed image in the West: mezzotint (Heilbrunn Timeline of Art History, Metropolitan Museum of Art)