The artist Ai Weiwei at Tate Modern:
It turns out that each seed is in fact a unique porcelain replica, hand-painted in Jingdezhen and fired at 1,300 degrees. Some 1,600 artisans worked for two years to make 100 million husks with a combined weight of 150 tonnes: a mass project, its collective spirit now abroad in London.
Comparative advantage at Wikipedia.