Zhang Yiming (right), an expert on spirit money, exhibits and talks about his collection of spirit money in an effort to lift the veil on this mysterious world. Zhang Yang (left), his only son, returned home to carry on the legacy in 2005. Father and son share the goal of creating a "bamboo paper arts village" in Zhonggang. (Jimmy Lin)

Traditional Chinese festivals often include offerings of incense, food, and "spirit money" to the gods and one's ancestors. The currency, the "legal tender" of heaven and the underworld, comes in a variety of types and denominations. But, even though spirit money is a familiar part of folk cultural practices, few of us can divine the meaning of the obscure text with which it is inscribed.

Long considered nothing but superstition and "corpse money," spirit money remains in active circulation. Why are some individuals still collecting the currency and promoting this unusual industry?

"Spirit money's value derives not only from its practical applications, but also from the text, drawing, carving, printing, and ideas that constitute this folk art," states Zhang Yiming, a student of spirit money for over three decades. "Take the printing of the bills. Each image originates with an earthy, naturalistic woodblock print. The lines are complex but succinct, fluid and skilled, each stroke of the -carver's knife manifesting piety and respect."

Pulling a "Boy God" bill and a "Hua Gong and Hua Po" bill from his collection, Zhang points out the image of a child clutching a string of copper coins printed on the Boy God bill. He says this reflects the Boy God's obligation to care for one's hua-cong. (In folk religion, hua-cong encompasses one's health, good fortune, and descendents.) Individuals wanting to know the gender of an unborn child, or wishing to have a child of a particular gender, can, with the help of a priest, hold a ceremony intended to explore their hua-cong, seeking the guidance of the child god and asking for protection of their hua-cong.