General information about Silk Fibres and Silk Fibres Production

by All Naturals, Published 25 June 2022


Mulberry Silk is made from the cocoons of Bombyx mori silkworms (also known as silk moths).

The cocoons consist of two main natural proteins called fibroin and sericin.

The higher the thread count, the more durable the fabric, and more costly.

Momme weight

Momme (mm) is used to measure the quality and density of silk fabrics.

1MM = 4.3056 grams per sq. meter

16MM = 69 grams per sq. meter

19MM = 82 grams per sq. meter

22MM = 95 grams per sq. meter

25MM = 108 grams per sq. meter and so on…


Momme is the weight of silk that determines its thickness. Usually, for silk pillowcases and silk bedding 20 momme and above is preferred, however for scarves thinner silk of 8 - 19 momme is recommended. 

Momme is a unit of measurement, much like thread count in Cotton. The silk fibres are much thinner than the cotton fibres so a large thread count can be easily reached and alternative unit of measurement is used.

Momme describes the silk’s weight and density. A high momme means there is more strands of silk per 100 yards of fabric, for this reason the fabric is heavier. the weight of the fabric then gives the momme. The higher the momme number the higher the quality and the more durable the fabric is. Momme usually ranges from 11-momme to 25-momme. What you have to consider when using the silk fabric is the purpose. 19-momme is more popular which is much higher than a 11 Momme, which is still considered quite low in quality, whereas 25 Momme can be too heavy to use for bedding and clothing.

Grades of silk 

The Western standards are established as letter and number combination type of grades of silk.

The silk material is graded on an A, B, and C scale. The letters represent the quality of the silk.  The finest silk is given a grade A and the lowest given a grade C.  A number is added to take the grading a step further.  6A is the highest grade that can be achieved and so is the best quality silk you can buy. 

We offer high grade silk products as well as some lower grade, for the obvious reason that customers should have not only expensive choice, but also a good choice of budget options available. All silk products on our website are checked to be 100% genuine silk main material, with some exceptions between 95%-100%. as mentioned in the landing front page announcement. 

OKEO-TEX Standard 100 certified would mean that they are free from harmful substances.  

Types of silk 

There are different types of silk known around the world. There are some less popular silks such as Anaphe silk, Spider silk, Coan silk, Ahimsa silk, Art silk (Bamboo silk) and Fagara silk. There are also Eri silk, Muga silk, and Tussar silk.

Eri Silk is produced from Samia Racini or Samia Cynthia feeding on the castor plant. and it is produced from domesticated worms. It is commonly produced in North-East India and some parts of Japan, China and Thailand. It is white in colour, displaying a woolly, cotton-like quality to it when spun into yarn, especially Ahimsa silk.  

Muga Silk is produced from Antheraea Assamensis feeding on soalu plants' aromatic leaves. It is produced from semi-domesticated worms. It is exclusively produced in the Assam region of India and hence in limited supply. It is very glossy, has high sheen, and is lustrous and golden in colour that increases with age. It has good ultra-violet rays absorption (85.08%) and it is an excellent sunshield for your skin. It is prized for use in the traditional dress of the region.

Tussar Silk is also known as Tasar Silk or Vasna Silk. It is produced from Antheraea Paphia / Antheraea Mylitta D feeding on plants Asan and Arjun.

Wild Indian Silk is produced mostly in the Bilaspur, Champa and Raigarh districts of Chhattisgarh in India. It is a natural fibre with colour ranging from yellowish beige to brown. It creates a rustling sound when rubbed together and has the ability to crease/wrinkle easily especially when interacting with water. Its unique feature is its unevenness and coarse, rough texture. 

Mulberry Silk

The production involves silk worms feeding on the leaves of the Mulberry tree. The best-known silk is obtained from the cocoons of the larvae of the Mulberry silk worm Bombyx mori. The silk worms feed on Mulberry leaves before creating a cocoon made from one long strand of silk.
Mulberry silk is highly coveted for its long fibre (up to 1 mile long), pure ivory colour with rich lustre, evenness and soft feel. Mulberry silk is recognised the world over as the best quality of silk.

Silk of all types is mostly produced in China (82% of global production) India (15%) and 22 other countries make up the balance of global supply.  

According to the International Sericulture Commission, 70%-90% of the silk produced globally each year is Mulberry Silk. 

Silk is prized for its impressive hypoallergenic and antimicrobial properties, and it is not known to cause irritation when in contact with sensitive skin. 



The table below describes the test requirements for grades from 6A to F.

Grades of raw silk – GBT 1797-2008 Raw Silk Quality Standard by, or as follows in GB/T 1797-2008_English: PDF (GB/T1797-2008) ( and in GB/T 15551-2016: Related standards ( where you can see it in its original content. 


GB/T 1797-2008 (GBT 1797-2008)

GB/T 1797-2008_English: PDF (GBT1797-2008)

Standard IDContents [version]PDF
GB/T 1797-2008EnglishRaw silkGB/T 1797-2008ValidGB/T 1797-2008


Click here to show a live Google Book.  

Click here to view and access a PDF document. 



Standard IDGB/T 1797-2008 (GB/T1797-2008)
Description (Translated English)Raw silk [Quasi-Official / Academic version - translated by Chinese Institute]
Sector / IndustryNational Standard (Recommended)
Classification of Chinese StandardW40
Classification of International Standard59.060.10
Word Count Estimation10,122
Date of Issue2008-08-06
Date of Implementation2009-06-01
Older Standard (superseded by this standard)GB 1797-2001
Quoted StandardGB/T 1798-2008
Drafting OrganizationZhejiang Cathaya International Co., Ltd.
Administrative OrganizationNational Standardization Technical Committee silk textile branch
Regulation (derived from)National Standard Announcement 2008 No.12 (Total No.125)
Proposing organizationChina Textile Industry Association
Issuing agency(ies)Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China; Standardization Administration of China
SummaryThis standard specifies the twisted silk dress and barrelled requirements, inspection rules, packaging and logo. This standard applies to the nominal fineness 69 den and below not soak silk.

GB/T 1797-2008 Raw silk ICS 59.060.10 W40 National Standards of People's Republic of China

and also:

GB/T 15551-2016 (GBT 15551-2016)

Chinese standards (related to): 'GB/T 15551-2016'

Standard IDContents [version]Standard Title (Description)See DetailStatusGoogle Book
GB/T 15551-2016EnglishMulberry silk fabricsGB/T 15551-2016ValidGBT 15551-2016
GB/T 15551-2007EnglishMulberry silk fabricsGB/T 15551-2007ObsoleteGBT 15551-2007
GB/T 15551-1995EnglishSilk fabricsGB/T 15551-1995ObsoleteGBT 15551-1995



Standard IDGB/T 15551-2016 (GB/T15551-2016)
Description (Translated English)Mulberry silk fabrics
Sector / IndustryNational Standard (Recommended)
Classification of Chinese StandardW43
Classification of International Standard59.080.30
Word Count Estimation9,969
Date of Issue25/4/2016
Date of Implementation2016-11-01
Older Standard (superseded by this standard)GB/T 15551-2007
Drafting OrganizationZhejiang Silk Technology Co., Ltd., Zhejiang Ya Ying Group Co., Ltd., Wanli Lee Group Co., Ltd., Xin Yuan cocoon Silk Group Co., Ltd., Jiangsu Huajia Silk Co., Dali (China) Co., Ltd., Jin Fuchun Group Co., Ltd., Zhejiang Pakistan
Administrative OrganizationNational Silk Standardization Technical Committee (SAC/TC 401)
Regulation (derived from)National Standard Announcement No
Proposing organizationChina Textile Industry Federation
Issuing agency(ies)General Administration of Quality Supervision, Inspection and Quarantine of the People Republic of China, Standardization Administration of the People Republic of China


There are two standards described in the above two tables: the GBT 15551-2016 Mulberry Silk Fabrics Standard and the GBT 1797-2008 Raw Silk Quality Standard.

China is the country that formulates both standards.

As China’s silk trade accounts for about 80% of the global silk market, the standards are widely used internationally.

That’s why “grade 6A” is everywhere, yet not much information is readily available.

Some other countries that have developed their own raw silk quality standards include Italy, India, and Japan.

The Italian raw silk electronic inspection grades are from 5 to 0, 6 in total;
Indian raw silk grades are 4A, 3A, 2A, A, B, C, D, E, 8 in total;
Japanese raw silk grades are from 6A to B, 7 in total.
Japan’s grade 6A raw silk production is much less engaged in global trade. Japan itself is a traditional country of silk consumption, with silk imports 10 times more than the number of exports.

So, although Japan also has 6A grade available, unless otherwise specified, the term “grade 6A” is based on Chinese standards, and the 6A grade raw silk product is also made in China. 

The lack of an international quality certification is shown using Amazon as an example.

Amazon returns over 1,000 search results for “6A silk pillowcase”, and over 5,000 search results for “silk pillowcase”. This quick search on Amazon shows that potentially over 20% of silk pillowcases for sale are “6A grade silk”.


At the same time, according to the 2017 China Silk Industry Development Report, the production of 6A grade raw silk is less than 1% of all production.

Such incoherence in the statistics shows the need for other ways to identify the quality of silk products available on the market.  



If you feel confused or hesitant about the best choice for your needs, then just apply common sense within your budget and be assured that you will have a good bargain. Although natural materials are unique and differ from source to source, they all have one main quality - they derive from nature itself. That itself is the best for your health and the environment.

The following suggestions are to help you get the best quality silk products available on the market and within your budget: 

Focus on how you feel

If your silk product  is comfortable to wear or sleep on, there is no need to worry about whether it’s 6A or any grade. For example, 5A and 6A silk are high-grade silk with an indistinguishable level difference.

Check measurable indicators

You can check out the momme count, or check if it is 100% silk.


Choose higher momme count products

Low-grade raw silks would never be used to produce high-grade fabrics, as they are more prone to cause fabric defects and lower the fabric quality and weave.  

Also, low grades of silk are commonly used only for rugs, bedding filling, or pillow fillings, and they are unsuitable for producing clothing and therefore will never come in contact with your skin.

Lower grade silk is produced from the same cocoons as higher grade silk, it just usually comes from the inner side of the cocoon, and the health benefits are the same. 

The so called ''higher grade'' silk quality is mainly about the quality of the weave, the lumps/pockets of air within the weave and the visual smoothness, texture and appearance of the fabric. 

Low grade silk fibres can be spotted visually as they are slightly different in colour and appearance, not so smooth and well shaped. The material itself is the same and is produced from the same moth. 

Genuine silk when blended with synthetics loses some of the properties such as it being thermoregulating, breathable and in most cases it is no longer completely smooth to the touch.

Your main consideration should be always if it is genuine silk, and further narrowing of the silk quality would include mainly the momme count. Also, for aesthetic lovers, the beauty, the texture and the weave of the fabric, could add to the pleasure of enjoying the comfort of the silk products you wear.