Organology
While acoustics dictated the general form and construction of the guqin, its external form could and did take on a huge amount of variation, whether it be from the embellishments or even the basic structure of the instrument. Qin tablatures from the Song era onwards have catalogued a plethora of qin forms. All, however, obey very basic rules of acoustics and symbolism of form. The qin uses strings of silk or metal-nylon and is tuned in accordance to traditional principles.
Ancient guqins were made of little more than wood and strings of twisted silk. Ornaments included inlaid dots of mother-of-pearl or other similar materials. Traditionally, the sounding board was made of Chinese parasol wood firmiana simplex, its rounded shape symbolising the heavens. The bottom was made of Chinese Catalpa, catalpa ovata, its flat shape symbolising earth. Modern instruments are most frequently made of Cunninghamia or other similar timbers. The traditional finish is of raw lacquer mixed with powdered deer horn, and the finishing process could take months of curing to complete. The finish develops cracks over time, and these cracks are believed to improve the instrument's sound as the wood and lacquer release tension. An antique guqin’s age can be determined by this snake like crack pattern called "duanwen" (断纹).
Read more about this topic: Guqin