Weft

A weft is a narrow strip of hair fibres sewn or bonded onto a backing band, used as the basic building block for wigs and wig extensions.

A weft is simply a row of hair fibres — whether synthetic or human hair — that have been stitched or bonded along one edge to create a flat, ribbon-like strip. That top edge is what gets attached to a wig cap, a clip, or another base, while the rest of the fibres hang freely to look like natural hair. Most ready-made wigs are constructed from machine-sewn wefts layered across a cap base, and loose wefts sold by the bundle let you customise or repair a wig yourself. When you add wefts to an existing wig, you typically sew or glue the backing band directly to the wig cap. The method you choose affects how secure and natural the result looks, so it is worth checking the entry on adding wefts to a wig for more detail on each approach.