The design of fabric warp and weft density should also be combined with the use of the fabric. For example, the characteristic of the gauze fabric is thin and transparent, in order to maintain this characteristic, in addition to the selection of thinner thread density of the warp and weft thread, should also reduce the warp and weft density. In order to make the fabric maintain good elasticity, not weak, not splitting, the warp and weft density tends to balance as much as possible, and gives the warp and weft yarn more twist. For example, when designing horn silk, in order not to affect the sound quality and maintain excellent permeability, the warp and weft density should also be reduced as much as possible. Another example for a variety of decorative silk, such as Chinese painting with twill, book binding fabric, paste wall silk, gift box with brocade, etc., in the premise of ensuring the decorative effect, can greatly reduce the warp and weft density. On the contrary, in order to make the silk taffeta used for the production of high-end dresses, the density of the fabric is usually increased more than that of ordinary plain fabrics in order to make the fabric hard and crisp, and fully reflect the unique "silk" characteristics of the real silk.

The theoretical density can be calculated by the interweaving of the diameter of the silk thread and the structure of the fabric (wool fabric has been introduced), but this calculation density is not completely practical, because the production conditions of each production unit are different, and the above five factors affecting the density design make the actual density produce a certain difference.

In the actual production process, the weft density of the fabric is smaller than the warp density, mainly because: the raw material used in the warp yarn is better, the machine tension is large, the silk thread is smooth, and the mercerization is sufficient, which has a greater impact on the texture of the fabric. And the warp wire density is generally finer than the weft wire, which is conducive to improving production efficiency. At the same speed, the weft density is small and the output is high. In addition, the weft density is small to facilitate production, and it is convenient to remove the weft when weaving defects occur.

The ratio of warp density to weft density should be determined according to the linear density of warp and weft yarn, organizational structure and the use characteristics of the fabric. If the ratio of warp and weft density of georgey yarn is very close, it is generally not less than 10%, and the density of satin fabric is very high. The ratio of warp and weft density differs by 50%-60%.

From the design point of view of the new varieties, if there are no special requirements, the weft density of the plain fabric should be less than 20%-30% of the warp density, the twill is 30%-40%, and the satin grain is about 50%.

If the weft density of single-layer fabric is greater than the warp density, it is unreasonable and should be avoided. However, heavy weft fabrics, especially jacquard fabrics composed of multi-colored weft, may be greater than warp density, which is the need of the structure, and can be treated as a special case.