Overview
Until modern era, the guqin's strings were always made of various thicknesses of twisted silk 『絲/丝』, but since then most players use modern nylon-flatwound steel strings 『鋼絲/钢丝』. This was partly due to the scarcity of high quality silk strings and partly due to the newer strings' greater durability and louder tone.
Read more about this topic: Guqin Strings