Ai Weiwei, one of China’s leading conceptual artists and an outspoken social commentator, has carpeted Tate Modern's Turbine Hall with millions of porcelain sunflower seeds, each intricately hand-painted.



In this film he talks about his motivation, and goes back to the Chinese city of Jingdezhen to meet some of the 1,600 artisans who created the seeds for him.