The Fangyuan brand is a world-renowned trademark owned by Yixing Zisha Craft Factory.

The Fangyuan brand trademark is also known as the first purple sand brand in China. It is China's earliest purple sand trademark recognized by the world and represents the highest standard of Chinese purple sand production technology.

In the 1970s and 1980s, with the boom in earning foreign exchange from exports, the Fangyuan brand logo of the Zisha Factory began to appear. It is usually presented in the form of a label, and only a few high-quality pots have the square garden label engraved on the pot.

Official-made Zisha teapots of Fangyuan level are extremely rare in the market, and high-quality teapots with the Fangyuan brand trademark engraved on the teapots are almost extinct in the market. In 2018, a Yixing Zisha Factory government-made teapot with square and round markings that was returned to the UK and engraved with square and round marks was sold for 2.2 million yuan after fierce bidding.

Fortunately, in 2018, Yixing Zisha Factory launched the Zisha 1972 official purple sand manufacturing project. It was built according to the highest export-grade standards in the 1970s, using Huanglongshan No. 4 Well mud specially supplied to the Zisha Factory. Moreover, each pot lid is engraved with the Fangyuan brand logo, which represents the highest standard of contemporary Chinese purple clay craftsmanship and fills the market gap that has been lacking in official purple clay for decades.