The different qualities of silk

Are you wondering about the different qualities of silk? Or how do you know if silk is quality? To answer these questions, we need to share with you a little of the history of silk and present to you the different parameters to take into account when talking about silk quality.

On the origin of silk: China, Japan and Europe

There are several myths and legends regarding the origin of silk, which has long remained a mystery to civilizations. However, it is in China that it has been known for more than 5000 years. Silk weaving is attested there from the end of the Shang dynasty (1046 BC). China occupied and still occupies a dominant position in the production of raw silk, that is to say raw silk obtained by the simple unwinding of the cocoon.
The arrival of silk in Western Europe dates back to the late Middle Ages . Then in the 19th century, it underwent a significant phase of industrialization. This industrial and economic boom will be followed by a decline due to competition in certain Asian countries as well as the epidemics which affected silkworms in France. These difficulties were therefore not without consequences since silk production subsequently became mainly Asian again.

Silk is the common thread of commerce and faith bringing people together, particularly on the very famous Silk Road . Despite the fact that its diffusion was rapid, silk production remained exclusively Chinese for three millennia, with the exception of Japan.

Many men and women have impacted the creation of silk, its manufacturing techniques and its evolution.

According to the China National Silk Import and Export Corporation (CNSIEC), the total area under mulberry cultivation in 1996 was approximately 865,000 acres (old agrarian measure, which refers to land area ). Cocoon production was 403,000 tons and raw silk production was 59,000 tons.

Very diverse qualities of silk

The qualities of silk are very diverse and can be appreciated for different reasons: Fineness, shine, solidity or resistance, beauty of colors, density of the fabric, properties of silk.
In the collective imagination, silk is light, fluid, sensual and delicate. Thanks to its thermoregulatory properties, it insulates in winter and cools in summer. All these characteristics justify the enthusiasm that there may have been around this material but also why it is so qualitative.

But then, how do you recognize good quality silk?

Silk is a fiber with which we must be very careful. It quickly becomes possible to confuse good quality silk with synthetic satin, for example. At first glance, silk has irregularities and offers a shiny or matte finish like the Benu Blanc pillowcases.

Why do we mention satin?

Satin is often confused with silk because satin is shiny. But satin is not a material, satin is a weaving technique . There are multiple satins: cotton satin or polyester satin. If you find a satin pillowcase at a low price, be careful, it is generally polyester satin, a petroleum derivative, and it has no beauty properties.

Different tips exist to recognize real silk: touch the material, take into account the price because silk is an expensive material, inspect the weave and the shine of the material... 100% silk fabrics produce when they are burned ash, not a mass like plastic when burned.
Be careful, it is easy to be fooled by fabrics with striking similarities (viscose for example).

There are also several kinds of silk, determined by their weaving, such as silk satin, silk muslin, silk twill, silk organza... Organza and muslin are fabrics made with the weave " CANVAS”, the difference comes from the density of the fabric or the type of silk threads used.

What are the different types of silk?

To be more precise in the various categories of silk, you should know that different types of silk exist. For example there is:

• Raw silk which is a continuous thread of approximately 1000 to 1200 m. This silk has a shiny finish
• The silk schappe which is a discontinuous thread of fibers ranging from 8 to 30 cm. This silk is matte and a little softer than the others. This is the “waste” of raw silk. The term “waste” can have a negative connotation but it only refers to cocoons that are unusable in spinning, for example when cocoons are pierced, stained, or threads broken during spinning. The longest fibers are those which will give the schappe and the shortest will give the silk bourette
• The silk bourette which is a discontinuous thread of very short fibers, less than 8 cm. This silk is matte, with a feel similar to linen. Its threads are indeed thicker and very strong.

Momme, mommé, silk mommes and quality

What does silk momme mean? Chinese or Japanese origin?

According to the Dictionary of Silk, the momme or mommé is an imperial Chinese measurement concerning the weight per meter of a fabric. The momme is equivalent to 4.4 grams per meter2. For example, an 8 momme fabric gives 35.2 grams per meter. This is an interesting criterion for evaluating silk, it allows you to determine its density and weight. The more mommes a silk has, the more resistant it will be and will prolong its longevity. We will look for silks of 19 to 25 momme for bed linen for example.

But the number of mommes does not necessarily indicate quality: there are superb light weight silk fabrics. The silk chiffon will be well below 19 mommes and yet we absolutely cannot say that it is of lower quality.

What are the different silk mommes and what are their characteristics?

Momme weight varies between fabrics. Below 16 mommes, we will instead find the textile family (clothing, accessories, lingerie).
For bed linen, especially silk pillowcases, moms tend to start at 19.

22 mommes is the upper level and a density which is very satisfactory for a pillowcase.

At Benu Blanc, we have selected a silk woven and manufactured in France to make our 25 momme silk pillowcases (112 g/m2). This density makes it a matte silk, very slightly shiny and non-slip which resists very well to machine washing.

If you have followed carefully, several criteria must be taken into account to identify good quality silk. The type of silk, its quality and its density are obviously essential indications. But the quality grade is just as important and significant when choosing a silk.

What is a silk grade? Is this important for the quality of silk?

The silk grade is a grading scale that gives a measure of the quality of a raw silk . Like any other fabric and material, some are of excellent quality, others of poor quality. So be careful not to be fooled with fabrics or products that appear qualitative.

What is the best quality of silk?

This classification includes 11 possible silk grades for raw silks (6A, 5A, 4A, 3A, 2A, A, B, C, D, E and F).
There is a lettered part and a numbered part. We'll explain!
The scale ranks the letters between A and F, each representing a different quality of silk. As you can imagine, A is the best quality, F is the least good quality.
Grade 6A is the finest quality of silk. The grades will depend on several parameters: color, cleanliness, fiber length, fineness differences, breakage, tenacity, etc.
The silk producer therefore sorts these raw silk threads during an inspection and classifies them into different grades.

You should know that the grade of the silk is not obligatory . Indeed, originally, this grade system was put in place by Japan to achieve tariff levels. And what's more, the grades only apply to raw silk.

What are the different certifications for silk?

OEKO-TEX certification for silk

The STANDARD 100 OEKO-TEX certification legally ensures the conformity of textile products, which have passed various controls. It further certifies that a product distinguished with STANDARD 100 has been verified with certainty for potential harmful substances integrated into it.

The Oeko-tex label for silk: a quality label

The Œko-Tex Standard 100 label, also called in French 'Confiance Textile', is a quality label.
It guarantees the quality of textiles and the products used during their production, for workers, but also for consumers and for the environment .
It ensures the production of materials and products without any trace of toxic substances. It was established in 1992 by the Austrian Textile Research Institute ÖTI and the German Research Institute Hohenstein. It allows all consumers to check whether the certification of a product is still current with a certification number.
At any stage of processing, the OEKO-TEX® system will be the one that will quickly detect and remove potential sources of problem substances. A check must take place when a textile product undergoes further processing or a change in its chemical composition is made. The more intensive and sensitive the contact of a product with the skin, the higher and stricter the requirements in terms of human ecology.
There are 4 classes of Oeko-Tex standard 100 products. They are determined based on the adhesion between the product and the skin. This means that anti-allergic standards will be much more demanding with the products most in contact with the skin.
Bed linen, for example, is part of class II because this class includes products in direct contact with the skin.

What does the Oeko-tex label guarantee?

The Oeko-tex standard was created to standardize the manufacturing process of textile materials in the international market. This does not work on all materials that exist, but especially on textiles without any harmful products present in their composition.

How to obtain Oeko-tex certification?

To obtain Oeko-Tex certification in France, the company must send a file to the IFTH (French Institute of Textiles and Clothing). The latter will take care of carrying out various laboratory tests using samples of products or materials. If they meet the requirements, then the certificate is issued for one year. Regular audits subsequently take place to ensure continued compliance with the standard during on-site inspections and sampling.

What is the difference between a label and a certification?

A label is what certifies the performance of a specific material. The label is not regulated by law unlike certification, which is. It is possible that a private organization, such as an association, is the one that issues a label.

The GOTS label: a label focused on organic products

The GOTS label, or Global Organic Textile Standard, certifies dignified working conditions but also respect for the environment of companies, their products, their production and transformation processes. In addition, it ensures that they do not harm the health of consumers. Checks also take place once a year.

The GOTS organization is made up of four organizations specializing in organic farming and responsible organic textile production.

What are the requirements for GOTS certification?

GOTS certification, which is a paid certification, has many environmental requirements. To have this “organic” GOTS label, a company must attest to the composition of its textile products. They must be composed of 95% organic fibers. To have the label 'composed of organic fibres', they must only be composed of 70% organic fibres.

Many chemical components that are harmful to the environment and highly polluting are obviously prohibited, such as products used for printing, bleaching and coloring. This is to avoid finding their presence in water and soil, which could damage the ecosystem.

Therefore, all compounds are examined to determine whether they meet basic environmental requirements such as non-toxicity and biodegradability.
The use of Genetically Modified Organisms, such as modified cotton, is strictly prohibited. Dangerous inputs such as toxic heavy metals or aromatic solvents are also prohibited.

To obtain this certification, all packaging must be recyclable, whether paper, cardboard or product labels.

In addition to its environmental requirements, GOTS certification also has social and health ones. For example, a GOTS certified company must meet many criteria, such as the abolition of forced child labor, adequacy of wages and decent working hours.
It must also ban chemicals harmful to health and ensure quality in technical terms of work and finished products.
This certification provides the end consumer with a credible guarantee.

The GRS standard for silk

The GRS standard, Global Recycled Standard, was created in 2008 by the Control Union Certifications. International and voluntary, it is responsible for establishing certification criteria for recycled content, chain of custody, social and environmental practices and restrictions on chemical composition.

This meets the needs of companies who want to verify the recycled content of their materials and products and control responsible social, environmental and chemical practices linked to their production.
GRS certification includes a high minimum percentage of recycled content, at least 50% is required, and additional social and environmental requirements related to the processing and use of chemicals.

What are the objectives of the GRS?

The GRS label has several objectives, the first being to reduce or even eliminate the negative impact of production on people and the environment. This production is guaranteed responsible and offers real traceability to the consumer.
Next, it wants to provide assurance that the products are indeed processed in a more climate-friendly way. Stakeholders are engaged and company communication must be completely transparent.
And finally, it wants to encourage a greater proportion of recycled content in products.
It applies to businesses engaged in ginning, spinning, weaving, knitting, dyeing, printing and sewing in more than 50 countries.

So where does Benu Blanc silk fit in?

The Benu Blanc silk pillowcases are made of silk schappe, which allows us to obtain this very characteristic matte finish. However, silk grades do not apply to schappe, so we cannot grade it. In fact, they only apply to raw silk. Additionally, grades are only one of multiple indicators of silk quality.
Our silk scarf is Oeko-tex certified and has a density of 25 mommes, which gives it resistance in the machine and over time. Its weave is taffeta, also called canvas.
Finally, it is woven in France, in Auvergne Rhône-Alpes, the cradle of French silk. It is made 5 kilometers from its place of weaving. To our knowledge, Benu Blanc is the only company to make 25 momme silk pillowcases woven and made in France.

Who were the major influential figures in the world of silk?

As said previously, many people influenced the discovery of silk but also the scale and importance it was able to take on among consumers.

This goes back a long time, when certain royal families used silk. This is the case of King Darius III (336 BC), of the Persian royal family, for example.

Zheng He born in 1371, admiral of the imperial fleet and the most famous Chinese explorer who traded several commodities such as gold, porcelain and even silk. Its routes are true examples for the new Silk Road.

Many weavers, designers, embroiderers and manufacturers of silk fabrics also left their mark on their era. But to tell you about all this, we will have to dedicate a new blog article to it!

[1] Dictionary of silk, Boucher JJ, 2014, Lanore editions

Photo of Silk in Lyon silk fabrics: Pierre-Aymeric Dillies