What were ancient koto strings made of? Don't tell me that it was also today's metal wrapped wire,

Historically, guzheng strings have gone through several stages, the earlier is the general use of animal sinews air-dried for the strings (deer sinews), there are also animal hair for the strings (horsetail), this kind of strings of the advantages of the sound is soft, the disadvantage is the volume is small, easy to go out of tune, the use of the life of a short period of time. In recent times, nylon strings began to be used instead, but the change is not significant. The Chaozhou zheng uses bare steel wire strings instead, achieving a soft, delicate, multi-rhythmic playing style, with increased volume, but on the hard side.

Before the 1950s, silk strings were used on the Chinese guzheng, dyed vermilion, emerald green, or cyan in the Tang Dynasty, and occasionally the tendons of the mourning chickens were used as strings. The use of silk strings can be traced back to the Spring and Autumn period, in China's earliest collection of poems, the Book of Songs, there are two kinds of silk stringed instruments, indicating that China's highly developed silk sericulture industry in ancient times, to the design and manufacture of musical instruments to lay a material foundation for the design and manufacture of the process, it can be said that the silk string technique is the excellent representative of China's musical instrument manufacturing technology.