Yarn, Luo's organization is more complex than the general silk, its warp silk is intertwined with each other and tangled weave, the surface of the transparent yarn eyes. Later, in the Ming and Qing dynasties, the yarn eyelets covered the surface of the fabric is called yarn, the yarn eyelets are distributed in rows at regular intervals, called Luo.

China's ancient so-called yarn, refers to the square hole yarn, it is not twisted warp, but sparse intervals, leaving holes, that is, the modern fabric science on the false gauze Luo organization, in our country in ancient times is called the square hole yarn.