Volume 3, Chapter 12:
Making a Cord
Cords may be made from silk embroidery or cloth thread. Elegant colors include light green or the color of incense. Red and purple are vulgar. The length (of a thread) should be around three feet, four or five inches. Weigh out three-tenths of an ounce. Divide the thread into seven equal bunches. Each bunch has two ends. Take one end and have a helper stand opposite on the left, who pinches one end. Pinch the other end, using the right hand thumb and index finger. Take the thread heads and wind to the left, gradually making the threads tight. After tightening, take the threads, and bend and turn them towards the center. Now take the two ends and pinch up into equal parts. Allow the two parts to twist together, and become a cord. Where the two ends evenly come together, addition use a thread to tie them up. Do not allow them to become loose or knot up.
 This is the cord used to capture the “fly-head” knot at the qin bridge and is used for fine tuning of a qin string.
 Remember there are ten Chinese inches to a foot, so 34 to 35 inches in total. Also one can estimate about 1.25 English inches to a Chinese inch of this time.
 See the Introduction for conversion information here. These are Chinese ounces (錢).
 One bundle for each string, hence seven in all.