Momme Weight Explained: How to Choose the Right Silk Bedding (And What the Numbers Actually Mean)

You found the silk bedding you want. The photos look incredible. The product description promises something about being smooth, breathable, and temperature-regulating. And then you see it, a number. 19 momme. Or 22 momme. Maybe 25 momme. No explanation. No context. Just a number that's supposed to mean something.

So you open a new tab and search. And somehow, twenty minutes later, you're deeper into a rabbit hole of thread counts, silk grades, and mulberry versus tussah, and you still don't know whether to buy the 19mm or the 25mm.

Sound familiar? This guide is here to break down everything the listing didn't explain.

By the time you finish reading, you'll know exactly what momme weight means, how it affects the feel and durability of your silk bedding set, and which weight is right for your sleep style.

In this guide:

• What is momme weight?
• Why momme weight matters more than thread count
• The momme weight scale: 19mm, 22mm, 25mm compared
• Quick comparison: Which momme weight is right for you?
• Does higher momme weight always mean better silk?
• Silk grades explained: Grade A and Grade 6A
• What is mulberry silk — and why does it matter?
• Which momme weight should you choose?

What is Momme Weight?

Momme weight (abbreviated as mm or written as "momme") is the standard measurement used to describe the weight and density of silk fabric. Think of it as the silk equivalent of thread count in cotton, except momme weight is actually a reliable indicator of quality, which thread count often isn't.

In simple terms, momme weight describes how many pounds a piece of silk fabric would weigh if cut to 45 inches wide and 100 yards long. The higher the number, the more silk fibre is packed into the weave, the heavier, more durable, and more opaque the fabric becomes.

So when you see 19 momme silk sheets on a product listing, you're being told that the silk is on the lighter, more breathable end of the bedding range. A 25 momme silk bedding set uses more silk per square inch, making it heavier, more lustrous, and longer-lasting.

Why Momme Weight Matters More Than Thread Count for Silk

Most silk retailers won't tell you this: thread count is a cotton measurement. It counts the number of threads woven into one square inch of fabric. Applied to silk, it's largely meaningless. And in some cases, misleading.

Silk is a continuous filament fibre. Unlike cotton, which is spun from short staple fibres, silk threads are extremely long and fine. Counting them per square inch doesn't tell you much about quality. A high thread count in silk can actually indicate thinner, lower-quality filaments packed together to inflate the number.

Momme weight measures the fabric itself, the actual amount of silk you're getting per unit. A 25 momme mulberry silk sheet contains significantly more silk than a 12 momme sheet, and you'll feel the difference immediately.

When you're comparing silk bedding sets, always look for momme weight first. If a listing only shows thread count and never mentions momme, treat that as a red flag.

The Momme Weight Scale: What Each Number Means for Bedding

Not all momme weights are created equal, and not all of them are appropriate for bedding. Here's how the scale breaks down in practice:

• Below 15 momme: Too lightweight for bedding use. Silk at this weight is typically used for scarves, linings, and lightweight clothing. It snags easily and won't hold up to regular washing.
• 16–18 momme: Entry-level silk bedding. You'll find this weight at lower price points. The feel is noticeably softer and more delicate, but the trade-off is durability. These sheets are more prone to pilling and snagging, and they tend to lose their sheen faster with washing.
• 19 momme: The everyday luxury sweet spot. This is the most popular weight for silk bedding, and for good reason. At 19 momme, the fabric is lightweight and exceptionally breathable, ideal for hot sleepers, warm climates, and year-round use. It feels smooth and cool against the skin without the heaviness that some sleepers find uncomfortable. Our 19 momme Grade 6A mulberry silk bedding set and 19 momme Grade 6A duvet cover are both built at this weight for exactly this reason.
• 22 momme: The mid-weight premium. Step up to 22 momme, and you'll notice a richer drape, more substantial feel, and greater durability. This is the weight that holds up best to frequent washing without losing its quality. It works in all climates and is the right choice if you're making a longer-term investment in your bedding. Our 22 momme Grade 6A double-sided silk duvet cover sits at this weight.
• 25 momme and above: Top-tier, heirloom-quality silk. The most luxurious end of the bedding range. At 25 momme, the silk is noticeably heavier with a deep, lustrous sheen that becomes more beautiful over time. It's the most durable weight available and the one that most closely resembles what you'd find in a five-star hotel suite. This is the weight of our 25 momme Grade 6A mulberry silk bedding set — our flagship product.
• 30 momme: Reserved for accessories. At this weight, silk is too heavy for sheets and duvet covers but exceptional for pillowcases and hair accessories, where durability and surface smoothness matter most. Our 30 momme Grade 6A silk pillowcase uses this weight for exactly that reason.

                                              30 momme silk pillowcase

Quick Comparison: Which Momme Weight is Right for you?

Does Higher Momme Weight Always Mean Better Silk?

This is the question most buyers get wrong, and it's where a lot of unnecessarily expensive purchases happen.

Higher momme weight means more silk, more durability, and a heavier feel. But "better" depends entirely on what you need.

If you run hot at night, a 25 momme silk bedding set may actually feel less comfortable than a 19 momme option, simply because the heavier weight retains slightly more warmth. The 19 momme fabric breathes more freely, which is precisely why it's the right choice for hot sleepers and anyone living in a warmer climate.

If you wash your bedding frequently, 22 or 25 momme will hold up better over time. Higher momme weight is more resistant to the wear that washing introduces, meaning the fabric keeps its sheen and softness for longer.

The other important factor, and one most buyers don't know to look for is silk grade. A higher momme weight doesn't compensate for lower grade silk. A 19 momme, Grade 6A mulberry silk sheet will outperform a 25 momme, Grade B sheet in feel, appearance, and longevity. The two measures work together. You need both.

Silk Grades Explained: What Grade A and Grade 6A Actually Mean

If momme weight is the first thing to look for on a silk listing, grade is the second.

Silk is graded based on the length, consistency, and purity of its filaments. The grading scale runs from A (standard quality) through to 6A (the highest grade commercially available).

Grade A silk uses long, consistent filaments with minimal imperfection. It produces a smooth, even fabric with good sheen and a soft hand feel. 

Grade 6A is the top of the grading system. The filaments are the longest, most uniform, and most lustrous available. The fabric produced at Grade 6A has an exceptionally refined sheen, a silkier surface feel, and greater resilience. This is the grade we use for our 19 momme Grade 6A duvet cover and 22 momme Grade 6A double-sided duvet cover — products where the quality of the silk surface matters most and all our other products.

Silk grades are not a marketing invention — they conform to an internationally recognised classification system established by bodies including the International Sericultural Commission, the global intergovernmental organisation for silk industry standards. A brand that discloses grade is using a verifiable, industry-wide language. One that doesn't is making you take their word for it.

What is Mulberry Silk, and why Does it Matter for Bedding?

You'll see mulberry silk on quality silk listings, including all of ours. It refers to the species of silkworm; Bombyx mori  which feeds exclusively on mulberry leaves to produce silk.

Mulberry silk is the gold standard for bedding for three reasons: the filaments are longer and more uniform than those from wild silkworms, the resulting fabric is smoother and more consistent, and the natural white colour means it dyes evenly, producing richer, truer colours.

      close-up of 100% mulberry silk fabric showing momme weight texture difference

The alternative is tussah silk, also called wild silk, produced by silkworms that feed on various leaves in the wild. Tussah silk is coarser, less uniform, and naturally a golden or tan colour. It has its uses in fashion and home décor, but it's not the silk you want against your skin for eight hours a night.

When you see 100% mulberry silk bedding set on a listing, it's telling you that the silk came from Bombyx mori silkworms — the right raw material. When you see just silk without qualification, it's worth asking what kind.

All Sisimi silk products are made from 100% mulberry silk. Every listing in our range specifies the momme weight, the silk grade, and the mulberry silk source because these are the three details you deserve to know before you spend money on silk bedding.

When checking a silk listing, look for OEKO-TEX® STANDARD 100 certification — an independent global standard that verifies a textile product has been tested against over 1,000 harmful substances. It's one of the clearest signals that a brand is being transparent about what's in their fabric.

Which Momme Weight Should You Choose? A Simple Decision Guide

If you're still unsure after everything above, here's a straightforward framework:

• Choose 19 momme if: you sleep hot, live in a warm climate, prefer lighter bedding, or are buying silk for the first time and want to experience the breathability that makes silk different from cotton and linen. Start here. Our 19 momme mulberry silk bedding set is the right entry point into the Sisimi range.
• Choose 22 momme if: you wash your bedding frequently and want it to last, you sleep in a range of temperatures throughout the year, or you want a more substantial feel without the full weight of 25 momme. Our 22 momme duvet cover is built for exactly this buyer.
• Choose 25 momme if: you're making a deliberate long-term investment in sleep quality, you prefer cooler room temperatures, or you want the most luxurious feel and appearance that silk bedding can offer. Our 25 momme Grade 6A silk bedding set is the flagship product in the Sisimi range — and the one designed to last.
• Choose 30 momme for pillowcases and accessories: the extra weight at the surface that touches your hair and face overnight makes a measurable difference in friction reduction and moisture retention. Our 30 momme Grade 6A silk pillowcase uses this weight for that reason.

The Bottom Line

Momme weight is the number that silk listings often show and rarely explain. Now you know what it means, how it relates to silk grade and material quality, and which weight is right for your specific situation.

The three things to look for on any silk listing before you buy:

1. Momme weight — 19mm for breathability, 22mm for balance, 25mm for luxury and longevity

2. Silk grade — Grade A or above; Grade 6A for the highest quality available

3. Material — 100% mulberry silk, not just "silk" or "satin"

4. OEKO-TEX® STANDARD 100 certification 

If a listing shows all four clearly, you're dealing with a brand that stands behind what they're selling.

Explore the full Sisimi silk bedding range — from 19 momme everyday luxury to 25 momme heirloom-quality sets, all crafted from Grade A and Grade 6A 100% pure mulberry silk.