The intaglio is an engraving of a material and is the opposite to cameo work. This technique far older than cameo work, and its origins can be traced back to the Sumarians of 3,000 B.C. who created roll seals from agate. This practice of intaglio carving was used extensively on seals and fobs manufactured during Georgian and Victorian times. The usual motif was the crest of a coat of arms, but occasionally a complete armorial can be found. Other motifs included a bird with a letter in its beak, a sailing ship, or a name. On intaglios the subjects were engraved in reverse, so that a positive impression would result when the seal was pressed into sealing wax. It should be remembered that an intaglio does not necessarily have to be in stone, or gemstone, for many signet rings, for example, exist on which the intaglio is engraved into its gold. The most common materials used for the carving of antique intaglios were: agate (all colours), quartz (all colours), nephrite jade (green), and rarely sapphire (blue, white, yellow).