Although practices similar to heat setting are used in the finishing
of almost all fabrics, the term heat setting, strictly speaking, refers only to thermoplastic man-made fibers
. Because of the thermoplastic
nature of most man-made fibers
(they change their shape when heat is applied), certain features, such as pleats, can be made permanent by treating them under very high heat. Heat setting usually gives a smooth appearance to a fabric and sets its final measurements. Boarding, a process in the rnanufacture of stockings, is a type of heat setting.