Girih

Girih (Persian: ‎‎, "knot"), also girih sāzī (گره سازی, "knot making") or girih chīnī (گره چینی), is an Islamic decorative art form used in architecture and handicrafts (book covers, tapestry, small metal objects), consisting of geometric lines that form an interlaced strapwork. In Iranian architecture, gereh sazi patterns were seen in banna'i brickwork, stucco, and mosaic faience work. Girih has been defined as "geometric (often star-and-polygon) designs composed upon or generated from arrays of points from which construction lines radiate and at which they intersect."

Straight-edged symmetric shapes are used in girih. Girih typically consists of a strapwork that form 6-, 8-, 10-, or 12-pointed stars separated by polygons and straps, and often they were drawn in an interlacing manner. Such patterns usually consist of a repeating "unit cell" with 2-, 3-, or 6-fold rotational symmetry that tiles the plane with no gaps.

The three-dimensional equivalent of girih is called muqarnas. It is used to decorate the underside of domes or squinches.

The girih style of ornamentation is thought to have been inspired by the Syrian Roman knotwork patterns dating back to the 2nd century AD. The predecessors of the girih form were curvilinear interlaced strapwork with three-fold rotational symmetry. The Umayyad Mosque (709–715), in Damascus, Syria has window screens made of interlacing undulating stapwork in the form of six-pointed stars. Early examples of Islamic geometric patterns made of straight strap lines can be seen in the architecture of the surviving gateway of the Ribat-i Malik caravanserai, Uzbekistan (1078).

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