Marco Polo, the Venetian traveler, merchant and explorer, wrote of the method he saw used in the East to extract the dye from the indigo plant which grows wild in India and other parts of Asia.

Indigo contains a beautiful blue color which was used in dying clothes long before Marco Polo saw it. In America, for example, garments dyed with indigo have been found in the ancient tombs of the Incas of Peru. The ancient Egyptians also knew about the indigo plant and garments dyed with it have been found in tombs dating back 4,000 years. According to Julius Caesar the ancient Britons indigo which they obtained from the woad plant.

There are about 300 different varieties of the indigo plant, some growing only in America while others are found only in Asia. The oldest method of extracting indigo from the plant is to grind the plant is to grind the plant up in vessels containing water and ammonia. A yellowish liquid is produced, which changes color as oxygen from the air enters it. It then deposits a muddy sediment at the bottom of the vat which is the actual dye used to color cloth.

Until the end of the nineteenth century indigo dye was obtained entirely from plants, but today it is mostly produced by the chemical industry.