A strip of fabric sewn along the edge of a carpet or rug to prevent fraying and give a finished look, as on area rugs and stair runners. A hand-knotted rug is normally finished differently: the weaver wraps the weft several times around the outermost warp to form the overcast, or selvage, usually a rounded, corded edge (sometimes flat, or in a contrasting wool) whose regional style helps experts tell where the rug was made.
The woven-in side edge of a hand-knotted rug, made during weaving as the weft is wrapped several times around the outermost warp to form a rounded, corded band. Depending on the region, the wrapping may use wool of a contrasting color, use the warp itself, or be kept flat rather than round, so the edge is one clue experts use to place a rug's origin. The word overcasting names this same edge and also appears in lists of common rug repairs.
An edge finish in which yarn is wrapped over and over around the outer edge of a rug, by machine or by hand, forming a rounded, rope-like band. It is the usual finish on the long sides of machine-made rugs (fringe usually marks the warp ends), and the way a worn edge of a hand-knotted rug is rebuilt (the repair called overcasting). The original edge of a hand-knotted rug is normally a selvage, woven in as the weft wraps the outermost warp during weaving, rather than an applied serge. On hand-made pieces, the evenness of the serging is a quick clue to the care taken in finishing.