Momme, pronounced 'mummy', is the unit used to measure the weight and density of silk fabric. One momme equals 4.340 grams per square metre. Higher momme means denser, heavier, more substantial silk. Silk products range from around 6 momme (chiffon) to 30+ momme (structured garments). For sleep masks and pillowcases, 22 momme is the industry sweet spot.

What does momme mean in silk?

Momme is a Japanese-origin unit of weight adopted globally by the silk industry. It measures how much silk is packed into a given area of fabric. Think of it like thread count for cotton, except more meaningful because silk's weight per square metre is a more honest measurement of fabric density than the number of individual threads.

What is a good momme for silk pillowcase?

22 momme is the sweet spot for silk pillowcases. Below 19 momme the fabric is too thin and pills quickly. Above 25 momme starts to feel overly heavy on a pillow. At 22 momme, you get substantial feel, durability of 3 to 5 years with proper care, and enough density to deliver the full benefits of silk (reduced friction, thermoregulation, moisture wicking).

Is 22 momme silk worth it?

Yes, for products in regular contact with skin — pillowcases and sleep masks specifically. 22 momme silk delivers substantially better performance on every meaningful metric than lower momme weights: better light blocking, better durability, better thermoregulation, less pilling. The price gap between 16 momme and 22 momme is real but small; the quality gap is significant.

Why don't cheap silk brands publish momme weight?

Because publishing a low number makes the product harder to sell against higher-momme competitors at similar price points. Momme weight correlates directly with raw material cost — a 22 momme fabric uses significantly more silk than a 16 momme fabric. Brands using lower momme silk often omit the specification entirely and use vague marketing language like 'luxury' or 'premium' instead. If you can't find the momme weight on a product page, assume it's below 19.

What is Momme Silk? The one number that matters

April 24, 2026

Technical Guide · April 2026

What is Momme Silk?
The one number that matters

If you only learn one technical term about silk before buying, make it this one. It separates genuine luxury from cheap imitation more reliably than price or brand.

1,500 words · 6 min read

Momme, pronounced mummy, is the unit used to measure the weight and density of silk fabric. It's abbreviated "mm" on product listings and ranges from about 11 on the cheap end to 30+ on the luxury end. Everything about how a silk product feels, performs and lasts ties back to this single number — which is why every serious silk specialist publishes it openly, and why most cheap silk brands quietly don't.

If you're about to spend money on anything silk — pillowcase, sleep mask, scarf, underwear — the momme weight is the single spec that tells you more than price, brand or marketing copy combined. This guide explains what it is, how to read it, and what to buy.

The Definition

The technical definition

One momme equals 4.340 grams per square metre. So a 22 momme silk fabric weighs around 95 grams per square metre; a 30 momme silk fabric weighs around 130.

The practical translation: higher momme means denser weave, more silk per square inch, and a heavier, more substantial feel. Think of it like thread count for cotton sheets, except more meaningful because silk's weight per area is a more honest measurement of fabric density than the number of threads crammed into it.

Historical note: the word comes from the Japanese silk industry, where momme (匁) was a traditional unit of weight. The silk trade adopted it globally because it gave a precise way to specify silk fabric independent of the local weight system. It's one of the few textile specs that's genuinely international and standard.

The Scale

The momme scale, explained

The practical ranges you'll encounter and what each actually means.

6–11

momme

Chiffon & gauze weight

Scarves, formal dresses, thin layering garments. Transparent, extremely lightweight. Not appropriate for anything pressed against skin overnight.

12–15

momme

Budget bedding weight

Common in Amazon listings and fast-fashion "silk" products. Thin, often transparent to light, pills within months. Most "silk sleep masks" under £20 are in this range.

16–19

momme

Entry-level luxury

Where many silk pillowcases sit. Adequate for pillowcases (the fabric is already layered over padding). Thin for masks — often leaks light at the edges of the nose and temples.

momme

The Sweet Spot

The gold standard for sleep masks

Dense enough to block light completely. Heavy enough to feel considered. Light enough to stay breathable through the night. This is the momme weight that silk specialists use and publish openly.

momme

Luxury bedding weight

Heavier, more substantial. Best suited to duvet covers and luxury pillowcases where the extra weight adds to the experience. For a mask, slightly heavier than ideal — can feel warmer in summer.

30+

momme

Structured silk weight

Stiff enough to hold a shape. Used in structured garments, formal jackets, and some luxury upholstery. Not what you want against your skin overnight — too rigid, too warm.

"A brand that publishes '100% mulberry silk' without the momme number is telling you it's low — and hoping you don't know what momme means."

The Tell

Why cheap brands hide it

Momme weight is directly proportional to raw material cost. A 22 momme pillowcase uses significantly more silk than a 16 momme one — roughly 40% more per unit area. That cost is real and it shows up in the retail price.

A brand selling a £15 "100% mulberry silk" pillowcase has almost certainly used 12–16 momme silk. If they disclosed that, most informed buyers would immediately compare it to a 22 momme product at a similar price and make a different decision. So the spec gets omitted. The product listing uses "luxury", "premium", "finest quality" — vague words with no technical meaning — and never says the number.

This isn't illegal, and it isn't always malicious. Some brands genuinely don't know — they're buying from suppliers who don't tell them. Either way, the end result for you as a buyer is the same: if the momme weight isn't published, assume it's low. A serious silk specialist publishes the number because the number is the point.

★ The one-line test

Before buying any silk product, search the product page for the word "momme" or "mm". If you can't find it, assume the weight is below 19 momme. Don't pay a 22-momme price for it.

What momme weight to buy for what product

Different silk products have different ideal momme weights. Here are the guidelines from the textile industry — not our marketing take, the genuine industry standard.

Sleep masks: 22 momme. Dense enough to block light completely, thin enough to stay breathable against skin for 8 hours.
Pillowcases: 19–25 momme. 22 is the sweet spot. Below 19 the fabric is too thin; above 25 starts to feel heavy on a pillow.
Bed sheets: 22–30 momme. Higher is better for durability as sheets take the most wear.
Duvet covers: 25 momme+. Heavier fabric sits and drapes better on a filled duvet.
Scarves and hair accessories: 12–16 momme. Lightness and drape matter more than density.
Silk pyjamas: 19–22 momme. Comfort balance between drape and weight.