Grades of Silk: Scale, Weight & Types Explained
For shoppers choosing a silk pillowcase or bed linen, this guide explains grades of silk, Momme weight and fibre types, so you can compare quality before you buy.
Grades of silk at a glance
Silk grades describe the quality of the raw material. The grading sequence shown here runs from F, E, D, C and B through A, 2A, 3A, 4A, 5A and 6A, with Grade 6A at the top. Momme measures the weight of the woven fabric, while Mulberry, Eri, Muga and Tussar identify silk types. For bedding, look at all three together: grade, weight and fibre. Mayfairsilk uses Grade 6A pure Mulberry silk, with 25 Momme pillowcases and fluid 22 Momme sheets and duvet covers. Weave, finish, stitching and care also influence how the finished silk feels and wears through regular use.
How to Read Silk Quality Before You Buy
Most silk bedding is marketed with a single claim: "100% Mulberry silk." That tells you the fibre type but says nothing about the grade of the raw silk or the weight of the woven fabric, which are two important factors in how a pillowcase feels and wears. A 16-Momme Grade B Mulberry pillowcase and a 25-Momme Grade 6A Mulberry pillowcase are both technically "100% Mulberry silk," but their weight and surface can feel quite different.
Look for a label that states all three: the grade (6A is the highest), the Momme weight (22 to 25 for bedding), and the fibre type (pure Mulberry for the longest, most uniform strands). If any of those three is missing from the product listing, ask the brand for the specification before comparing prices.
Mayfairsilk specifies all three for its bedding. Sheets and duvet covers are woven from Grade 6A pure Mulberry silk at 22 Momme, pillowcases are finished at a thicker 25 Momme.
Silk quality: grade, type, weight and construction
Check |
What it describes |
Buying cue |
|---|---|---|
Grade |
Raw material quality under a named standard. |
6A is the top of the familiar A-series. |
Type |
The source of the natural protein fibre. |
Pure Mulberry silk for a smooth, even bedding surface. |
Momme |
Weight per unit area of silk fabric. |
22 Momme bed linen, 25 Momme pillowcases at Mayfairsilk. |
Weave and finish |
How yarn becomes the finished fabric. |
Even surface, soft texture and neatly finished seams. |
What Are the Different Grades of Silk?
The pyramid shows the full sequence: F, E, D, C, B, A, 2A, 3A, 4A, 5A and 6A. Grade 6A is the highest, with six levels in the A-series.
Grade A
Raw silk is tested and graded before it is traded in the silk market. The grade helps determine the price a lot can fetch, with Grade 6A commanding the highest prices among comparable grades. This assessment takes place at the raw-material stage, before the silk is woven into fabric.
Grade 6A is also rare. In a 2023 statement reported by tndNews, Clet Wandui Masiga, executive director of the Tropical Institute of Development Innovations (TRIDI), estimated that only 1–3% of global silk production met this grade.
Grade A is associated with high quality silk, made from long, even strands. The top A-series grades are valued for consistency and low levels of yarn defects. A single thread can stretch up to around 1,500 metres in its natural form, and when woven, the fabric stays lightweight, breathable, and smooth to the touch.
Grade A is further split into six sub-categories: 6A, 5A, 4A, 3A, 2A, and A. Of these, Grade 6A is the very best, and as with most commodities, the price reflects the quality.
This grade of silk is used in many Western wedding dresses, along with traditional Eastern garments such as kimonos and cheongsams. More recently, Grade 6A has become a favourite among buyers with discerning taste who refuse to compromise on their silk sheets and duvet covers.
Grade B
Grade B sits below the A-series in systems using that designation. More yarn irregularities can create an uneven surface across the woven fabric. A grade alone does not specify fibre length, colour or whether silk has been reeled or spun.
The result can be a less even feel than higher-grade silk, although finishing also influences natural shine. Lower-grade silk still has plenty of practical uses in the fashion industry. Sarees, kurtas, kaftans and other everyday garments benefit from silk's lightweight, breathable feel, but a garment type does not establish its silk grade.
Grade C
Grade C is a low-ranking grade in systems using that designation, with more irregularities than higher grades. Rough texture, unevenness and limited natural shine can affect the feel of lower-quality fabric. Colour and breathability cannot be established from the grade alone.
Silk floss is also used for stuffing silk pillows and filling silk duvets, since the floss sits inside the product rather than in direct contact with the skin. Filling has its own quality criteria and is not automatically Grade C.
Other Grades Of Silk
Below the A-series sit Grades B, C, D, E and F in the sequence shown in our pyramid.
Silk drapes, rugs, wall hangings and craft materials have different requirements from silk bedding or sleepwear. Appearance, texture and durability matter alongside softness against the skin. Short fibres can be spun into useful silk yarn, rather than being reeled as continuous filament.
How is raw silk tested?
Raw silk testing examines yarn size, evenness, cleanness, neatness and strength. The FAO silk-testing manual describes how testing and classification work. Published grading standards differ, so a supplier’s test report should identify the method used.
Higher-grade silk helps produce an even fabric that retains a smooth feel with proper care. Lower-grade material can have more defects and less consistency, increasing the risk of uneven wear. Shorter fibres need spinning, while long filaments can form continuous raw silk thread. Neither fibre length nor a grade alone predicts a product’s lifespan.
What Is Momme & How Does It Affect Silk Quality?
Momme (pronounced "mommy") is the unit used to measure the weight and density of silk fabric, rather than counting threads as thread count does for cotton. One Momme equals roughly 4.34 grams per square metre, and the higher the Momme number, the heavier the fabric. Durability also depends on yarn, weave, finish and care.
For silk bedding, Momme weight is one of the clearest quality signals. 19 Momme is a familiar bedding weight. For a denser, more substantial fabric, 22 to 25 Momme is our preferred range for sheets, duvet covers and pillowcases. Lighter silks can feel more delicate, while heavier silks can feel less airy. A higher number is not automatically better for every use.
At the same size, 25 Momme fabric weighs about 14% more than 22 Momme fabric. This is a weight comparison, not a promise of 14% longer life.
Silks below about 16 Momme are lightweight and can be sheer, depending on weave. They suit different uses from substantial bed linen. An airy scarf and a nightly pillowcase need different cloth.
Momme weights compared
Weight |
Approximate mass |
Our practical guide |
|---|---|---|
19 Momme |
82 g/m² |
A lighter bedding option. |
22 Momme |
95 g/m² |
Our sheets and duvet covers, with a fluid drape. |
25 Momme |
109 g/m² |
Our pillowcases, with a more substantial feel. |
4 Types of Natural Silk Fibre
Silk is produced by silkworms and comes in various types. The International Sericultural Commission identifies Mulberry, Eri, Muga and Tasar as four commercially important types.
1. Mulberry Silk
Mulberry silk is produced from the Bombyx mori silkworm (domesticated) which feeds on mulberry leaves. This silk is prized for its long fibres, which can reach around 1,500 metres in length, along with its pure ivory colour, rich lustre, and soft handfeel. The International Sericultural Commission describes it as the dominant commercial silk.
2. Eri Silk
Eri silk is produced from the domesticated Samia ricini silkworm (also classified as Samia cynthia ricini and Philosamia ricini), which feeds on the castor plant. It is most commonly produced in North-East India, with smaller pockets of production in Japan, China, and Thailand.
The fibre can be naturally white or brick red in colour and spins into a woolly, cotton-like yarn, a quality that becomes especially noticeable in Ahimsa silk.
“Peace silk” or “Ahimsa silk” describes a production approach intended to allow moth emergence, not a grade. Ask about the supply chain rather than assuming every Eri silk product follows the same method.
Eri is often sold as peace silk and has a heavier, woollier character than fine reeled silk. The Florida Museum’s wild silks collection describes its use in shawls, blankets and other silk items.
3. Muga Silk
Muga silk comes from the semi-domesticated Antheraea assamensis silkworm, which feeds on the aromatic leaves of the som and soalu plants. It is produced almost exclusively in Assam, India, which keeps supply limited and demand high.
Muga is known for its high sheen and golden colour, which deepens beautifully with age. It is traditionally used in Assamese ceremonial dress.
4. Tussar Silk (also known as Tasar Silk or Kosa Silk)
Tussar is a wild Indian silk produced from Antheraea paphia or Antheraea mylitta, both of which feed on Asan and Arjun food plants.
The natural fibre ranges from yellowish beige to brown, creases easily (especially when wet), and creates a faint rustling sound when rubbed together. Its signature feature is an uneven, coarse texture that gives finished fabric a distinct, rustic character.
Tussah silk commonly refers to silk from Antheraea pernyi, reared on oak leaves in China and neighbouring regions. Like other wild silks, it often has a darker, coarser character than pale Mulberry silk, though processing can create either a smooth or rough finish. Traditional garments and home furnishings use these differences to beautiful effect.
Weave and finish: what makes silk feel different?
Silk weaving changes the surface as much as the raw material. A plain weave, satin and crepe de chine produce different textures. Satin is a weave, not a fibre: pure silk satin and polyester satin have different compositions. Crepe de chine has a subtly textured feel, useful in silk garments. These names are not grades.
The dyeing process and finishing affect colour depth and handfeel. Fine silk can have a natural sheen without looking glossy. Our soft-touch matte finish gives a luxurious feel with a quieter surface. Read our silk versus satin guide.
Silk production, organic silk and peace silk
Sericulture is the cultivation of silkworms for silk production, beginning with host plants such as mulberry trees. Harvested cocoons are reeled or spun, then silk weaving and finishing turn yarn into cloth. This intricate process helps explain why silk costs more than many other fabrics.
Raw silk production can support rural livelihoods. The International Sericultural Commission highlights employment across farming, reeling and weaving. That social contribution does not make every silk product environmentally preferable.
Ahimsa or peace silk aims to harvest cocoons without killing the silkworms, allowing the moth to emerge before the cocoon is processed. Check how the producer implements that approach. Organic silk concerns certified agricultural practices, including restrictions on synthetic pesticides and fertilisers. Neither is a grade. GOTS explains organic fibre and processing certification; a factory’s certificate does not automatically certify every brand’s finished product.
Silk is a natural protein fibre that can biodegrade under suitable conditions. Research on silk biomaterials shows that processing affects degradation. Dyes, finishes and other materials in a finished product also matter. “Natural” is not a blanket eco-friendly claim.
Mayfairsilk: Grade 6A Pure Mulberry Silk Bedding for Your Nightly Comfort
All Mayfairsilk bedding is made of Grade 6A pure Mulberry silk, with Momme weights of 22 to 25.
Choosing silk bedding comes down to three checks working in your favour: a top-tier grade, a Momme weight built for nightly use, and a silk type known for long, even fibres. Match all three with good construction and proper care, and you have bedding worth choosing for nightly comfort.
This is the standard we hold ourselves to. Our sheets and duvet covers are woven in 22 Momme Grade 6A Mulberry silk, while our pillowcases step up to a thicker 25 Momme for extra durability where your hair and skin need it most. Browse our Mulberry silk bedding collection to find your set.
Start with a 25 Momme silk pillowcase for smooth contact with skin and hair. Extend the fluid drape to the whole bed with 22 Momme silk sheets. For bedtime and travel, explore our silk eye masks, or bring colour to your room with silk cushion covers. Check each accessory’s individual construction and filling details.
Silk’s naturally hypoallergenic nature and smooth surface can feel comfortable against sensitive skin. This does not mean allergy-proof. Silk’s smooth surface helps reduce friction against hair. Its breathability and natural thermoregulating qualities support temperature comfort rather than controlling body temperature. Discover the benefits of silk.
Silk pillowcases
25 Momme, for smooth contact with skin and hair.
Silk bed sheets
22 Momme, with a fluid drape.
Silk eye masks
Soft silk comfort, at home or away.
Silk cushion covers
Colour and print for the bed or sofa.
Frequently Asked Questions (FAQs)
What is the highest grade of silk?
Grade 6A is the highest grade on the commonly used A-to-6A raw-silk scale. It comes from long, unbroken Mulberry silk fibres that are pearl white in colour, selected for evenness and low levels of defects. This is the grade used in premium silk bedding and luxury garments where quality cannot be compromised.
Which type of silk is most durable?
Mulberry silk is valued for its durability because its long, even fibres weave into a smooth, consistent fabric. Higher Momme weights add to that durability, although construction and care also determine how the fabric holds up through regular use and washing. Muga silk is also known for strength and ages well, but it is produced in very limited quantities.
What should I consider when buying silk bedding?
Check three things before you buy: the type of silk (pure Mulberry is the gold standard), the grade (6A is the top tier), and the Momme weight (22 to 25 Momme is ideal for sheets and pillowcases). Also look for certifications such as OEKO-TEX Standard 100, which concerns testing for harmful substances. Check the current certificate number and scope for the product. Finally, review the brand's delivery terms, guarantee, and care instructions so you know what you are getting.
What kind of silk does Mayfairsilk use?
Mayfairsilk uses Grade 6A pure Mulberry silk, the highest quality grade available. Pillowcases are made in a thicker 25 Momme weight, while sheets and duvet sets are crafted in 22 Momme for the ideal balance of weight and breathability. Check each product page for its current specifications, construction and care details.
Is 6A silk the same as 25 Momme silk?
No. Grade 6A describes raw silk quality; 25 Momme describes fabric weight. Grade 6A silk fabric can be woven at different weights, including 19, 22 and 25 Momme. Compare both specifications.
Is Mulberry silk always Grade 6A?
No. Mulberry identifies the silk type, not its grade. The Bombyx mori silkworm feeds on mulberry leaves, but the raw silk produced still needs to be assessed for quality.
Does OEKO-TEX STANDARD 100 certify silk grade?
No. OEKO-TEX STANDARD 100 concerns testing for harmful substances. It does not certify Grade 6A, Momme weight or organic production. Confirm the certificate number and scope for the specific silk product.
How should I care for high-grade silk?
Follow the item’s care label. For Mayfairsilk bed linen, use a delicate cycle no hotter than 30°C and a detergent suitable for silk. Air dry in the shade, away from direct sunlight. Do not tumble dry. Read our silk care guide.
Sources and further reading
FAO: Silk reeling and testing manual, Chapter 11. Raw silk testing and classification differences.
China’s national standards platform: GB/T 1797-2008. Raw silk standard reference.
International Sericultural Commission: Types of silk. Silk types and their sources.
OEKO-TEX: STANDARD 100. The scope of harmful-substance testing.
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