the.com/openwork

Lace made of metal or wood: the holes are the point, not the gaps.

means A pattern of material (metal, wood, lace, or masonry) that is deliberately perforated or latticed, so the cut-away spaces form part of the design.

from A straightforward English compound of 'open' plus 'work' (as in craftsmanship or workmanship), dating to around the 1700s — the word simply names what it is: work that is left open rather than solid, whether in ironwork grilles, carved screens, or embroidered lace.

definition
ornamental pattern made by cutting or piercing material
used in
ironwork, embroidery, latticework, jewelry
strength trick
removing material can increase structural rigidity
etymology
literally work that is open, since 1600s
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