Strings (tennis)
The material used in tennis string can significantly affect a player's performance, and even health. Several materials are used to make tennis strings. They vary in terms of elasticity, durability, rebound efficiency, tension holding capability, and manufacturing cost, among other considerations.
Guqin
Until recently, the guqin's strings were always made of various thicknesses of twisted silk, but since then most players use modern nylon-flatwound steel strings. This was partly due to the scarcity of high quality silk strings and partly due to the newer strings' greater durability and louder tone.