Face changing, better known as Bian Lian, is considered one of the most mysterious of China's traditional performing arts. Originally a trick of the Sichuan Opera, only a few Chinese opera masters have been able to grasp the skill.

Stepping into Zeng's home, you will find many different glamorous and colorful masks covering the walls of the living room, most of them homemade. The bulk of these were inspired by the famous characters from The Romance of Three Kingdoms.

A renowned artist and one-time manager of Changsha Xiangju Opera House in Central China's Hunan province, Zeng has devoted himself to mask making and exploring the secrets of mask changing.

"It usually takes one month to make a mask, and it has to be in the summer so the paint can dry quickly," Zeng says. He has even tried to make a mask the size of a bean.

In 2004, Zeng became quite a controversial figure. He triggered a public backlash when he claimed he had successfully decoded the secrets behind Sichuan Opera face changing, an old skill considered to be a confidential national treasure. Many people accused Zeng of tainting this art.