Engraved or incised work on gemstones, glass, ceramics, stone, or similar material in which the design is sunk beneath the surface, the opposite of cameo and relief .
It is the most ancient form of gem engraving; the earliest known Babylonian cylinder seals date from с 4000 BC. The term intaglio is also used to describe printmaking processes in which the design is cut, scratched, or etched into a printing surface of copper, zinc, or aluminum; ink is then rubbed into the incisions or grooves, the surface is wiped clean, and the paper is embossed into the incised lines with pressure from a roller press. Intaglio processes are the most versatile of printmaking methods, as they can produce a wide range of effects.