Openwork removes parts of a metal surface so light passes through. It appears in incense burners, lamps, architectural screens, jewelry, astrolabe retes, boxes, and fittings. Piercing can be drilled, chiseled, sawn, or filed. The maker must balance ornament with structural strength, especially on thin sheet or delicate instrument parts.

Lathe turning can regularize circular forms, create rings, grooves, ridges, and polished profiles on vessels, candlesticks, stands, and instrument parts. On a cylindrical candlestick, turned moldings can frame engraved and inlaid panels. The page should show how rotational symmetry helps organize ornament.

Cut edges, repeated drill holes, filed bridges, turned grooves, and tool chatter are evidence of process. On an astrolabe, openwork is not just decorative; the rete must indicate star positions while remaining strong enough to move.