Silk was made from cocoons made from worms that are fed on mulberry leaves. Silk was important to China because since it was a prized export for China, since kings of distant lands would pay so much for it, and wearing silk is an important status symbol. They were also used for not only clothing, but also paper, fishing lines, bowstring, and canvas for paintings. It was kept a secret because kings and nobles of foreign lands paid high prices for silk, but unfortunately, in 550 A.D., two monks from the Byzantine Empire smuggled silkworm eggs out of China. Silk was even used as money in some Ancient Chinese dynasties. Merchants and peasants weren't allowed to wear silk like the nobles and kings can until the Qing dynasty.