Chou silk yarn, also known as oil silk yarn, is made from silk waste material. Its advantages include good breathability and strong drape, while its drawback is the short fiber length of the silk waste.

It is comfortable to wear in summer as it does not cling to the skin, and oil silk fabric is generally thicker and stiffer than other silk fabrics. However, due to the short fiber length of the silk waste and the potential presence of other impurities, oil silk is often woven to achieve a coarse or linen-like texture. The fabric surface is rough and lacks luster.