Gourd vessels like this were formed by placing a wooden mold around the young gourd and allowing the natural growth within these confines to form the shape and decoration. None of the decoration or the mark is cut by the knife, all is a mirror of the carved decoration within the mold. The earliest known use of such a technique appears to date to the Warring States period (480-221 BC). A mouthpiece for a musical instrument was found in a Chu tomb in Changsha, Hunan province. Though 16th century texts attest to the gourd-molding tecnique, the earliest extant examples appear to date to the reign of Kangxi.