Grades of Silk: Scale, Weight & Types Explained

Key Takeaways

- Silk is sorted into roughly 11 grades, with Grade 6A at the top for its long, pearl-white fibres, natural sheen, and absence of impurities.
- Momme measures fabric weight and density the way thread count measures cotton. For bedding, 22 to 25 momme delivers the best balance of softness, durability, and breathability.
- The four main natural silk types are Mulberry, Eri, Muga, and Tussar, with Mulberry accounting for roughly 90% of global production and producing the longest, most even fibres.
- Lower grades and lighter momme weights cost less upfront but fade, thin, and wear through faster, making the per-year cost higher than investing in top-tier silk from the start.
- Mayfairsilk bedding is crafted from Grade 6A pure Mulberry silk at 22 to 25 momme, OEKO-TEX Standard 100 certified, with a 30-night sleep guarantee on pillowcases.

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 the two factors that determine whether a pillowcase still feels smooth after six months of washing or starts pilling within weeks. A 16-momme Grade B Mulberry pillowcase and a 25-momme Grade 6A Mulberry pillowcase are both technically "100% Mulberry silk," but they perform nothing alike.

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, it is usually because the number wouldn't impress, and the price reflects a product that looks like premium silk on screen but feels and wears like something less in person.

Mayfairsilk lists all three on every product. Sheets and duvet covers are woven from Grade 6A pure Mulberry silk at 22 momme, pillowcases are finished at a thicker 25 momme, and OEKO-TEX Standard 100 certification confirms the fabric is free from harmful substances.

Mayfairsilk: Luxurious Slumber in Matte Silk

As Featured in Marie Claire, Harper's Bazaar & Vanity Fair

Experience True Silk Luxury: Get 25 Momme pillowcases that reduce friction on hair and skin, 22 Momme thermoregulating sheet sets with our signature matte finish, and limited-edition prints made in small, distinctive batches.

The Mayfairsilk Difference:

✓ Grade 6A Mulberry silk (the highest quality available)
✓ Thicker, more durable weave (22–25 Momme vs. standard 19)
✓ Natural thermoregulation for year-round comfort

✓ British-owned and designed
✓ UK-based warehouse for fast, reliable delivery
✓ 30-night sleep guarantee on pillowcases

Free Next-Day Delivery on orders of £50 or more (UK), €180 or more (EU), or US$180 or more (US). All taxes and duties calculated upfront, with no surprise charges.

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What Are the Different Grades of Silk?

Silk grading covers roughly 11 tiers in total, split between the six Grade A sub-tiers at the top and the letter grades that follow, right down to fibres too rough to rank.

Grade A

Grade A is the highest quality silk, made from long, even strands that are luminous pearl white and free from impurities. 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 silk produces shorter lengths of floss rather than the long, continuous strands found in Grade A. The colour is broadly similar to higher grades, but the fibre contains more clumps, which create small air pockets and an uneven surface across the woven fabric.

The result is a slightly rough feel and noticeably less of the natural shine seen in Grade 6A. Grade B lacks the smoothness needed for premium bedding, but it still has plenty of practical uses in the fashion industry. You will often see it in sarees, kurtas, kaftans, and other everyday garments that benefit from silk's lightweight, breathable feel without needing top-tier quality.

Grade C

Grade C is a low-ranking grade made from short, uneven floss. It has a yellowish appearance with brown dots. This grade of silk feels like cotton, and it has a rough texture. The floss is short in length with hardly any natural shine. It feels lumpy and is not as breathable as the other two grades of silk.

This type of silk is widely used for stuffing silk pillows and filling silk duvets, since the floss sits inside the product rather than in direct contact with the skin.

Other Grades Of Silk

The remaining grades extend to D, E, F, and fibres not eligible to rank at all. These are considered the lowest tier of raw silk, with short, uneven strands and very little of the strength or sheen needed for clothing or bedding.

Because they are unsuitable for silk bedding or sleepwear, these grades are usually turned into decorative or hard-wearing items such as silk drapes, rugs, wall hangings, and craft materials, where appearance and durability matter more than softness against the skin.

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, much like thread count for cotton. One momme equals roughly 4.34 grams per square metre, and the higher the momme number, the heavier, denser, and more durable the silk.

For silk bedding, momme weight is one of the clearest quality signals. Most silk bedding on the market sits at around 19 momme, which is considered the standard. For a noticeably softer, denser and longer-lasting fabric, 22 to 25 momme is the premium range for sheets, duvet covers and pillowcases. Lighter silks below 19 momme tend to feel thin and wear out faster, while silks above 25 momme can feel heavy and lose some of the airy comfort silk is loved for.

4 Types of Natural Silk Fibre

Person carrying a silkworm on a leaf

Silk is produced by silkworms and comes in various types.

1. Mulberry Silk

Mulberry silk is produced from the Bombyx mori silkworm (domesticated) or Bombyx mandarina (wild and less commercially viable), both of which feed 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. It makes up roughly 90% of all silk produced worldwide.

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 is naturally white in colour and spins into a woolly, cotton-like yarn, a quality that becomes especially noticeable in Ahimsa silk.

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 also a natural sunshield that absorbs ultraviolet rays and 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.

Mayfairsilk: Grade 6A Pure Mulberry Silk Bedding for Your Nightly Comfort

Woman sitting on her bed, using the Mayfairsilk Cream Silk Duvet Set

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. Miss one, and comfort or durability slips. Match all three, and you have bedding worth sleeping on for years.

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.

Frequently Asked Questions (FAQs)

What is the highest grade of silk?

Grade 6A is the highest grade of silk available on the market. It comes from long, unbroken Mulberry silk fibres that are pearl white in colour, free from impurities, and naturally lustrous. 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 widely considered one of the most durable natural silks because its long, even fibres weave into a smooth, consistent fabric. Higher momme weights add to that durability, which is why 22 to 25 momme Mulberry silk holds up far better through regular use and washing than thinner alternatives. 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 confirms the fabric is free from harmful substances. 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. Every product is OEKO-TEX Standard 100 certified, so you can sleep easy knowing the fabric is free from harmful substances.

*Note: The prices and product listings mentioned above are approximate and may vary over time or by location. Actual costs can differ based on pricing policies, provider experience, and market conditions.

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