Intaglio refers to incised (negative) image-making, and is the opposite of cameo. It's used in making engraved seals, where it leaves a raised design on the material being stamped, especially wax. 2002 Lincoln cent, obverse, proof with cameo Cameo is a method of carving, or an item of jewelry made in this manner. ... Seal on envelope A seal is an impression printed on, embossed upon, or affixed to a document (or any other object) in order to authenticate it, in lieu of or in addition to a signature. ...

It is also used in some pendants. A dramatic effect is a locket with a cameo and a matching intaglio.