Momme Explained: What Silk Weight Means and What to Buy

What is momme?

Momme is a unit of weight that silk sellers use to describe how heavy a silk fabric is. One momme equals 4.34 grams per square metre of silk fabric, so a 19 momme silk weighs about 82 grams per square metre, and a 22 momme silk about 95. A higher momme means more silk in the same area. It does not mean a better grade of silk, a better weave, or a better finish.

You will see momme on pillowcases, pajamas, sheets, scarves and dress fabric, usually with a number between about 8 and 30. The figure is useful because silk sellers all use it, but it is easy to misread. This guide explains where momme comes from, how to convert it, which weights suit which products, why it does not apply to polyester satin, and how to check that a seller’s number is real. For the same idea in the units used everywhere else, see our guide to GSM.

Where does momme come from?

Momme began as an old Japanese unit of mass, and it is still used for pearls as well as silk. Store norske leksikon, the Norwegian encyclopedia, describes it as an old Japanese mass unit, defined as one thousandth of a kan, and says that in 1891 Japanese mass units were given exact values relative to metric ones. For pearls, it gives 1 momme as 3.75 grams. For silk fabric density, it gives 1 momme as 4.34 grams per square metre, and notes that 25 momme equals about 108.5 g/m2 (Store norske leksikon, momme).

The two figures are different because they measure different things. For pearls, momme is a mass. For silk cloth, it is a weight per area, built from the old trade practice of weighing a standard piece of silk. Silk sellers commonly explain it as the weight in pounds of a piece of silk 45 inches wide and 100 yards long. We could not find that exact definition in a standards document, but the arithmetic matches the encyclopedia: one pound is 453.59 grams, and 45 inches by 100 yards is about 104.5 square metres, so 453.59 divided by 104.5 is 4.34 grams per square metre.

How do you convert momme to GSM and back?

Multiply momme by 4.34 to get grams per square metre, and divide GSM by 4.34 to get momme. The table shows common silk weights. For ounces per square yard, divide the GSM by 33.906, and our GSM guide has a converter that does all three at once. All the momme, GSM and ounce figures sit together in the Satin Database.

The right-hand column reflects typical retail use, not a standard, and sellers vary. Treat it as a map of what you will meet, not as a rule for what you should buy.

Is a higher momme better?

No. A higher momme means a heavier fabric, and heavier is only better for some uses. A 12 momme scarf drapes and floats the way it should, and a 30 momme one would feel stiff. A 22 momme pillowcase feels fuller and more opaque than a 16 momme one, but it is not automatically a better product.

• It is a weight, not a grade. Two silks of 19 momme can be very different if one uses finer yarn, a tighter weave or a better finish.
• Heavier can mean warmer. More silk per area traps more air, which suits cool rooms and may not suit hot sleepers.
• Heavier can mean less drape. A heavy silk satin hangs in larger folds and can feel stiffer. Our guide to charmeuse satin covers the fluid end of the range.
• Heavier costs more. More fiber is more silk, and silk is expensive. A price gap between 16 and 22 momme is partly just the extra material.

Which momme suits which product?

Choose by use, then check the weave and the fiber. These ranges are common in retail, and no standard sets them.

Can polyester satin have a momme?

Momme is a silk unit, and using it for polyester is a marketing habit, not a standard. You can convert any fabric’s GSM into momme with the same factor, so a 90 GSM polyester satin is about 21 momme on paper. The number then says only that the polyester weighs as much as a 21 momme silk. It says nothing about silk content, quality or feel. If a listing for a polyester satin quotes momme, treat it as a weight and read the fiber label.

A polyester satin and a silk satin of the same weight differ in absorbency, breathability, care and price. Our guides to silk satin and polyester satin explain those differences, and our satin vs silk comparison covers the choice between them in general.

How is momme different from thread count?

Momme measures weight per area, and thread count measures yarns per unit width. They are different numbers, and you cannot convert one into the other. Cotton sheets are sold by thread count, and silk is sold by momme. A silk with a high momme can have a low yarn count if the yarns are heavy, and a fine, dense silk can have a lower momme if the yarns are light.

For silk, momme is the more useful single figure, because it tells you roughly how much silk you get. For the full picture you also want the weave and the finish. A sheet with a high momme but a loose weave can feel flimsy, and a medium momme in a good weave can feel excellent.

How can you check a seller’s momme?

Weigh a swatch and convert the result. Cut a 10 cm by 10 cm square, weigh it in grams, multiply by 100 to get GSM, and divide by 4.34 to get momme. If the seller says 22 momme and your square comes to 0.80 g (80 GSM, about 18 momme), the claim is probably overstated. A scale that reads to 0.01 g is needed, and small errors in cutting and in moisture mean results within about 5 percent are normal. ASTM method D3776 covers the formal measurement of fabric mass per unit area, and includes an option for a small swatch (ASTM D3776, Mass per Unit Area (Weight) of Fabric).

1. Ask for the momme and the fiber content on the label, and not just in the title.
2. Check whether the figure is for the fabric before or after finishing, since finishing can change weight.
3. Weigh a swatch if you can, and compare with the stated momme.
4. Look at the weave and hand in a swatch, because momme tells you nothing about those.
5. Read the reviews for comments on opacity and durability, since they tell you how the weight performs.

What else matters besides momme?

Fiber, weave, finish and care matter as much as weight. Silk labelled with a high momme can still be a blend, a weighted silk or a poor weave. In the United States the Textile Fiber Products Identification Act requires fiber content labelling, and the Federal Trade Commission says misbranding of textile fiber products is unlawful (FTC, Textile Fiber Products Identification Act). Read the percentage on the label, and do not rely on the headline.

• Weave. Charmeuse, crepe de chine and other weaves feel different at the same momme. Satin weave gives gloss, and other weaves give a matte, crisp feel.
• Finish. Softening and calendering change hand and sheen without changing momme much.
• Dye and colour. Dark and strong colours can look richer on the same weight, and dye loading can change the weight slightly.
• Care. Heavier silk generally tolerates handling better, but it still needs gentle washing and no hot tumble drying.

What mistakes do buyers make with momme?

The common errors come from treating a weight like a quality score. Watch for these:

• Choosing the highest number. Heavier is not better for a scarf, a blouse or a hot sleeper, and it costs more.
• Comparing across fibers. A 22 momme polyester and a 22 momme silk weigh the same and are very different cloths.
• Ignoring the weave. Two silks of the same momme in different weaves feel and hang differently.
• Skipping the label. A headline that says “silk” can still be a blend, so read the fiber percentage.
• Trusting a single claim. If it matters, weigh a swatch and check the result against the stated momme.

What should you check before you buy silk by momme?

1. The fiber content and percentage on the label.
2. The momme figure, and whether it is for the fabric or the finished product.
3. The weave: charmeuse or another, and whether it is the satin weave you expect.
4. The use: pick a weight that suits sleeping, wearing or draping, not the highest number.
5. The care label and your willingness to follow it.
6. The return policy, so you can check opacity and weight at home.

How does momme change how silk feels and wears?

Weight changes five things you can feel: opacity, drape, warmth, body and wear. The links are practical, and they follow from having more or less fiber in each square metre. They are not exact rules, and weave and finish can bend them.

Colour interacts with weight. A dark colour in a light weight can still look rich and opaque, and a pale one may need a lining. If you are buying a pale silk for a blouse, hold a swatch over your hand in daylight and see how much shows through.

What does a heavier momme cost per gram?

A higher momme usually costs more per metre, but it can cost less per gram of silk. To compare fairly, convert each fabric into weight per metre of length, then divide the price. Say two silk fabrics are both 140 cm wide and both cost 25 per metre. A 16 momme silk weighs 69.4 g/m2, so one metre of length is 69.4 x 1.4 = 97 g. A 22 momme silk weighs 95.5 g/m2, so a metre is 95.5 x 1.4 = 134 g. At the same price, the first costs 25 / 97 = 0.26 per gram, and the second 25 / 134 = 0.19, about 27 percent less per gram of silk.

The reverse can also hold. If the 22 momme costs twice as much, it is more per gram, and you should ask why. Use this arithmetic to see whether a price rise matches the extra weight, and read it alongside the fiber label, since a blend with polyester weighs the same and costs far less than pure silk.

How should you care for silk of different weights?

Follow the care label first. In general, heavier silk handles a gentle wash a little better, and lighter silk needs more care. None of it likes heat, harsh detergent or the dryer.

• Wash cool and gently. Use a mild detergent made for delicates, and wash by hand or on a delicate cycle if the label allows it. Our washing guide has the steps.
• Skip bleach and strong enzymes. Silk is a protein fiber, and these products can weaken it.
• Dry in the shade. Sun fades dye and weakens silk over time.
• Iron low, on the reverse. Use a cloth, and test a hidden corner first.
• Store clean. Sweat and body oils attack silk when left in the fabric, so wash it before long storage.

Why should you trust this guide?

We do not sell silk and earn nothing from any brand named here. The 4.34 g/m2 conversion and the history of the unit come from Store norske leksikon, the labelling law from the Federal Trade Commission, and the weighing method from ASTM’s published description. Many silk sellers publish momme guides that put their own product ranges first, so we kept to the encyclopedia and to our own arithmetic. The retail ranges in the tables are what you will see in shops, not standards, and we did not test silk for this guide.

Frequently asked questions

What does momme mean in silk?

It is a Japanese unit of weight used for silk. In fabric terms, 1 momme equals 4.34 grams per square metre, so a 19 momme silk is about 82 g/m2. A higher figure means a heavier silk, not a better one.

What momme is best for a silk pillowcase?

Retail pillowcases commonly run from 19 to 25 momme. A weight around 22 gives a fuller feel, and 19 is a common lighter option. Check the weave and the fiber content as well as the number.

What momme is best for silk pajamas?

Many pajama sets are sold between 16 and 22 momme, which is soft, opaque enough and not too warm. Heavier suits cool rooms, and lighter suits warm ones. See our pajamas comparison for fiber choices.

Is 30 momme silk too heavy?

For clothes, it can be stiff and warm, but for furnishings and structured garments it is normal. For sleepwear and scarves, lighter is more common.

Is momme the same as GSM?

They measure the same thing in different units. Multiply momme by 4.34 to get GSM, and divide GSM by 4.34 to get momme. GSM can be used for any fiber, and momme is used for silk.

How many momme is polyester satin?

Polyester satin is not normally graded by momme. You can convert its GSM to momme, but the number only describes weight. Always check the fiber label.

Can I check momme at home?

Roughly, yes. Weigh a 10 cm by 10 cm swatch on a scale that reads to 0.01 g, multiply by 100 for GSM, and divide by 4.34 for momme. Results within about 5 percent of the claim are normal.

Does higher momme mean more durable silk?

Often a little, because there is more fiber to wear out, but weave, yarn quality and care matter as much. A well-made 19 momme silk can outlast a poorly made 25 momme one.

Final word

Momme is a weight, a useful and honest one, as long as you do not read it as a quality grade. Use the 4.34 factor to translate it, pick a weight that suits the product, and check the fiber, the weave and the label. If you want to see how weight changes the way satin hangs, read our drape and shine guide next.