More than 1,000 years of porcelain making has left Jingdezhen a rich legacy, which provided Gong with an insight into ancient procedures.

"I was able to find treasures in local households," he says.

In the early 1990s, he spent three years researching and deciphering the craftsmanship of blue-and-white porcelain made during the Ming Emperor Xuande's reign (1426-35).

"I found that the blue and white colors were thanks to the rich trace metal elements in their raw materials, which came from the Middle East and differed greatly from those sourced domestically," Gong says.

In terms of painting techniques, porcelain ware from the Ming Dynasty is mostly characterized by a free and easy expression, while that of the Qing Dynasty (1644-1911) is known for its more clear-cut strokes.

He then had to rediscover the ancient firing methods, which required repeated experimentation to discover the optimal temperature and the right mix of glaze materials to deliver a porcelain surface akin to jade.

By the end of the 1990s, he also managed to recover the porcelain-making process used during the reign of Emperor Chenghua (1465-87) of the Ming Dynasty.

Since then, Gong has studied hundreds of items of blue-and-white porcelain from ancient imperial kilns, which has allowed him to fully explore and research the evolution of their craftsmanship.

"During the Han (206 BC-AD 220) and Tang (618-907) dynasties, the original glaze used on Jingdezhen ceramics was prepared from rice straw ash that had been fermented. Its high iron content explains the brown color," Gong explains, adding that ancient people explored the use of local plant materials and eventually settled on ferns, which grow abundantly in the mountains and fields around Jingdezhen.

"As a result, clear and elegant blue-and-white porcelain was born," he says, adding that this plant material is the key to achieving the lustrous jade-like glaze and is ruined by modern electric and gas kiln equipment.