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Grades of silk: Grade 6A, the best quality silk

There are a number of materials such as cotton and linen that have brand names according to their quality (place of origin). But we can be unaware that there are actually grades of silk as well. Let’s see which one is the best quality and where we can get them!

There is a difference in the quality of yarn even if they are made of the same material.

In fact, there is a difference in the quality of yarns even in the same cotton. For example, Supima cotton and Sea Island cotton are so high quality that they can be used as brands. The quality is mainly based on the length of the fiber and the low level of impurities.

“Our fabrics are not just cotton!” or “Not just hemp!” You can find the name of the material in the product name, such as Supima Cotton or Saffiran Linen. Of course, even chemical fibers such as polyester have various functions added by changing the shape of the threads. However, in the case of natural fibers, it is not so much that functions are added, but rather the texture and appearance are changed to a higher quality. This means that raw materials are more important.

Who determines the grade of silk?

Do you know where silk yarn is made? In fact, it is said that 80-90% of silk yarn distributed in the world comes from China. China has started to determine the rank of silk in order to sell it to the rest of the world.

It was decided by a Chinese national agency, the Commercial Inspection Bureau.

This rank allows us to know at a glance whether the quality of the same silk is good or bad.

Grades of silk

According to China’s GBT 1797-2008 Raw Silk Quality Standards, the raw silk is divided into 11 grades, from 6A, 5A, 4A, 3A, 2A, A, B, C, D, E, to F. 

In grade A, Silk is classified into A~6A, and the higher the number, the better the quality. Silk 5A and 6A account for only 10% of the total supply and are used by high brands and top maison brands.

Silk quality standards are as follows

  • Uniformity of yarn
  • Minimal impurities
  • Minimal fluff
  • Tensile strength
  • Elongation

The yarns are ranked according to these criteria.

Grade 5A Silk

SLK120 12 mace silk habutae  Okura Shoji Co.

SLK120 本絹羽二重12匁[生地] オークラ商事

SLK180 16 mace

SLK270 16-mace silk twill

Silk using grade 6A for warp and grade 5A for weft

SLK160 16-mace silk satin

SLK200 20-mace silk crepe


We hope you have a better glance about silk and know what to look for when buying silk from now on. 

If you are looking for more silk fabrics, please visit ApparelX’s silk products list.

Hi guys, this is Jane, the editor of ApparelX News. As a foreigner living in Tokyo, I hope my posts will help international readers get an overview about Japanese fashion industry as well as Japanese culture!