Concise Bible Dictionary:

The cutting of words or designs on precious stones, as the names of the tribes on the breastplate and the shoulder-pieces of the high priest; and the words “Holiness to the Lord” on the plate of the miter. There was also the devising of “cunning work” for the tabernacle. For this service God endowed certain men with special skill, wisdom, and understanding. Devices were also engraved on seals (Ex. 28:11,21,36; Ex. 35:35; Ex. 38:23; Ex. 39:14,30; Zech. 3:9; 2 Cor. 3:7). Engraving is used metaphorically when God says He had graven Israel upon the palms of His hands, and thus had them constantly before Him (Isa. 49:16).