Some work by Robert D'Arista, courtesy of Lowell Gilbertson. D'Arista was one of my mentors in graduate school at American University. More work, and details on medium and dimensions can be found at http://www.robertdarista.com/
The works posted here are all drypoint engravings except for the first, which is a monotype, and the third, an etching. A drypoint is usually made by incising a metal plate with a sharpened stylus, which creates a furrow on one or both sides of the line, like the action of a plow through soil. This raised line holds the ink and, along with the wiping of the ink, imparts to the medium its characteristic qualities. Drypoint, of all the intaglio techniques, is the closest to drawing in its directness and its sensitivity to the pressures of the hand.
D'Arista often carried small, thin, copper plates in his coat pocket in place of a sketchbook, along with styluses that he fashioned from crushed shards of semi-precious stones.