Archaeologists in Xi'an have discovered a large-scale industrial facility from the Western Zhou Dynasty (c. 1046–771 BCE) specialized in the dyeing of imperial silk. The complex features an array of deep ceramic vats and a sophisticated drainage system designed to handle the runoff from large-scale textile processing. Analysis of the sediment inside the vats revealed traces of rare mineral pigments, including malachite and cinnabar.
The excavation also uncovered a hoard of bronze stirring rods and specialized stone weights used to keep silk submerged during the dyeing process. This discovery provides the earliest evidence of a centralized, state-managed "laboratory" approach to color production in ancient China. The facility was located near the royal palace, underscoring the importance of vibrant textiles as symbols of political and ritual authority during the Zhou period.