"As a child, I watched him burn patterns with heated pieces of metal, and I found it very magical," Niu says.

Bottle gourds have long been considered auspicious by the Chinese. Its shape made it an ideal container in the past. In ancient times, many doctors used bottle gourds to hold medicine and hung them at the front of their clinics. The practice saw the gourd evolve into a symbol of traditional Chinese medicine, denoting the presence of its practitioners.

Moreover, as a bottle gourd has many seeds, it has come to be a totem that bodes well for thriving offspring and bountiful grain harvests.

Bottle gourd pyrography is the art of decorating gourds by burning a graphic design onto the surface. The technique known as pyrography can be traced back more than 2,200 years to the Qin Dynasty (221-206 BC), but it was not until the end of the Ming Dynasty (1368-1644) that the art was first applied to gourds.

Gourd pyrography made its way from the folk world to the royal court during the early Qing Dynasty (1644-1911), where such items became collectible.

Skilled craftsmen have applied pyrography to turn ordinary bottle gourds into exquisite artwork.

The first step to making one is to pick a ripe and golden bottle gourd. As cultivation technology has improved, bottle gourds of varying shapes and sizes have come into being.

Then, the artist has to design a creative pattern before applying it. Skilled artists usually take advantage of the natural shape and texture of the gourd, using a heated tool or wire to burn, or scorch, the designs onto it, which can take on a three-dimensional appearance.

"If you make a mistake during the application process, it's back to the drawing board," Niu says.

Niu is the fourth generation of his family to continue the practice. His predecessor started using a self-made, smoke-free pyrography tool for his artistic creations, which caused a sensation at that time in Beijing.

Niu considers the feats of his generation to be another step further than that of his grandfather.