Charles Ellicott Commentary Exodus 28:11

"With the work of an engraver in stone, like the engravings of a signet, shalt thou engrave the two stones, according to the names of the children of Israel: thou shalt make them to be inclosed in settings of gold." — Exodus 28:11 (ASV)

The engravings of a signet. — Compare Note 2 on Exodus 28:9. Signets had already been mentioned in Genesis 38:18; Genesis 38:25; Genesis 41:42. Those of Egypt were for the most part rings, with cylindrical bezels turning on an axis. Those of Babylonia were cylinders, which were commonly worn on a string around the wrist. The engraving on the Babylonian cylinders is frequently of very fine quality.

Thou shalt make them to be set in ouches of gold. — The setting intended seems to have been a sort of open or filigree work, such as is very common in Egyptian ornaments of the time. The term “ouche”—more properly “nouch”—is derived from the old French “nouche,” a buckle or clasp (see Skeat’s Etymol. Dict., §5).