Selvedges are often up to 20mm wide and may differ from the body of the fabric in construction or weave or both, or they may be of exactly the same construction as the body of the fabric and be separated from it by yarns of a different colour. Although selvedges may contain fancy effects or may have brand names or fabric descriptions woven into or printed on them, their main purposes is to give strength to the edges of the fabric so that it will behave satisfactorily in weaving and subsequent processes.
a) Leno Edge
A set of threads that interlace with a leno weave either at the edge or in the body of a fabric. In the latter case, it prevents fraying when the fabric is severed in the direction of the warp.
When in the body of the fabric, a leno edge is often referred to as a "central selvedge". (See also splits)
b) Sealed Edge
The cut edge of a fabric that has been treated by heat or chemical means to prevent fraying of the edge.
c) Shuttleless-Loom Edge
1. In some cases, either one or both edges are different from the normal woven selvedge in that the weft is held in position at the turn by threads other than the warp threads, e.g. by the use of an independent thread to lock the weft in position at the edge, or by interlocking of the weft threads. In narrow-fabric weaving this type of edge is often called a "needleloom selvedge".
2. In other cases, the weft is severed just beyond the edge of the fabric and the cut end is tucked into the shed (q.v.) formed on the next pick.