Red strings are strings dyed with cinnabar. According to Yueji (The Book of Music), “the strings of the se in the ancestral temple are red and the sounds reach far.” So red strings have been in existence before the Qin Dynasty. The annotations prepared by Zheng Xuan (127-200) of the Eastern Han Dynasty read, “The sounds from red strings are harsh.” So the sounds from red strings are not pleasant. The use of red strings by later generations is mostly for imitating ancient practices. The production of red strings has never stopped until the late Qing Dynasty and the early years of the Republic of China. Thereafter, red strings are rare.

Nowadays, metal strings are used for qin. The whole set of strings has to be replaced whenever one of the strings breaks. Therefore nobody would retain used strings. At the time when silk strings were used, strings were in short supply. In addition, used silk strings can be re-used. So qin players treasured strings a lot and were used to retaining used strings. From these collections of the old strings used by qin players in the past, we will be able to get to know their habits, which are interesting details supplementing the history of qin.