Posted by Chris Ailey
on July 13, 2026
Silk pillowcases are having a quiet moment, and the language around them can feel needlessly technical. Momme, mulberry, grade 6A, long-strand fibre. It sounds like a code you need to crack before you can buy with confidence. In truth, only a couple of these terms really matter, and once they click, choosing a pillowcase that lasts becomes much simpler.
This is a calm, plain-English guide to what momme means, why mulberry silk is the grade worth paying for, and how to choose a pillowcase that still feels beautiful years from now.
Quick answer
Momme (pronounced "mommy" and written mm) is a unit of weight that tells you how dense and substantial a silk is. For pillowcases, 19 momme is widely considered the sweet spot: heavy enough to feel luxurious and wear well over years of washing, without the weight and cost of the 22 to 30 momme silks used for heavier bedding. Pair that 19 momme weight with genuine mulberry silk, which uses the longest and finest fibres, and you have a pillowcase that is smooth, breathable and genuinely durable. Every mulberry silk pillowcase in the Laud Sleep collection is woven to 19 momme for exactly this reason.
What does momme actually measure?
Momme is to silk what thread count is to cotton: a shorthand for quality, though a more honest one. It measures weight rather than the number of threads, so it is harder to inflate with marketing.
Technically, one momme equals the weight in pounds of a piece of silk measuring 45 inches wide and 100 yards long. You do not need to remember that. What matters is the pattern it creates: the higher the momme, the denser, heavier and more opaque the silk, and generally the longer it will last.
As a rough guide to the ranges you will see:
- 11 to 15 momme: light and delicate, often used for scarves and linings. Too thin to wear well as a pillowcase.
- 16 to 19 momme: the ideal window for pillowcases. Smooth, breathable and robust enough for regular washing.
- 19 to 25 momme: substantial silk used for pillowcases at the luxury end and for silk bedding.
- 25 to 30 momme: very heavy, opulent silk, usually reserved for high-end duvet covers and sheets, with a price to match.
This is why 19 momme sits at such a natural resting point. It is the top of the everyday pillowcase range: dense enough to drape well and survive years of laundering, yet still light enough to feel cool and quick to care for.
Why "mulberry" matters more than momme
Momme tells you how much silk is in the cloth. Mulberry tells you how good that silk is to begin with, and it is arguably the more important word of the two.
Mulberry silk comes from Bombyx mori silkworms raised on a strict diet of mulberry leaves. That controlled diet produces the finest, most uniform and longest silk fibres available. Because the strands are long and unbroken, they can be woven into a smoother, stronger and more even fabric than shorter-fibre silks, which are pieced together from broken filaments and tend to pill or wear unevenly.
You will often see mulberry silk described as grade 6A. This simply refers to the longest, most pristine strands within mulberry silk itself, the very best of an already premium fibre. When a pillowcase combines 6A-grade mulberry silk with a 19 momme weight, you are getting both quality of fibre and substance of cloth, which is the combination that actually lasts.
What 19 momme mulberry silk feels like to sleep on
Numbers are only useful if they translate into something you can feel. Here is what this particular specification tends to deliver night after night.
A cool, dry surface
Silk is naturally breathable and moisture-wicking, drawing a little warmth and humidity away from the skin rather than trapping it. It rarely feels cold, but it stays noticeably cooler than cotton, which is part of why so many people reach for it in warmer months. If temperature is your main concern, it is worth reading our honest comparison of silk and bamboo pillowcases and which feels cooler against skin, and our guide to whether silk pillowcases are good in hot weather.
Less friction for hair and skin
The smooth surface of tightly woven mulberry silk creates far less friction than cotton. In practice that means less tugging on hair overnight and less of the creasing and moisture-stripping that a rougher weave can cause. We cover this in more detail in the benefits of using a silk pillowcase.
Durability that justifies the price
A flimsy silk pillowcase is a false economy. The reason 19 momme mulberry silk costs more than a lightweight alternative is that it is built to survive dozens of gentle wash cycles without thinning, snagging or losing its sheen. Bought once and cared for well, it can outlast several cheaper pillowcases.
How to choose your silk pillowcase
With the two key terms understood, the rest of the decision is refreshingly simple.
- Confirm the momme: look for 19 momme. Anything advertised without a momme figure at all is often lighter than it should be.
- Confirm it is mulberry silk: ideally 6A-grade long-strand mulberry silk, not a silk blend or a shorter-fibre silk.
- Check the closure: a hidden zip or envelope closure keeps the pillowcase neat and stops the pillow slipping out.
- Choose your colour to suit the room: a silk pillowcase catches the light, so the shade reads slightly richer than a matte fabric. Softer tones such as white, sage and charcoal grey settle easily into most bedrooms.
- Plan for care: silk prefers a cool, gentle wash and air drying. Our guide to caring for luxury bedding, including how to wash silk, linen and bamboo, walks through the routine.
If you would like to feel the difference across a whole bed rather than a single pillow, the wider Silky Silks mulberry silk collection extends the same 19 momme quality into matching pieces.
Frequently asked questions
Is 19 momme good for a silk pillowcase?
Yes. 19 momme is generally regarded as the ideal weight for a pillowcase. It is dense enough to feel luxurious and to withstand regular washing, while remaining light and breathable. Higher momme silks exist but are heavier, pricier and better suited to bedding than to a pillow you launder often.
What is the difference between momme and thread count?
Thread count measures the number of threads woven into a set area and is used for cotton. Momme measures the weight and density of silk. Because silk quality depends on fibre weight rather than thread quantity, momme is the more meaningful measure for silk, and it is much harder to exaggerate.
What does mulberry silk mean?
Mulberry silk is produced by Bombyx mori silkworms fed only on mulberry leaves. This gives the longest, finest and most uniform fibres of any silk, which weave into a smoother and more durable fabric. It is considered the highest grade of silk available.
Are silk pillowcases worth it?
For most people, yes, provided the specification is right. A genuine 19 momme mulberry silk pillowcase offers a cooler, smoother surface than cotton, is gentler on hair and skin, and lasts for years when cared for properly. A cheap, low-momme silk is far less likely to deliver those benefits.
How do I wash a mulberry silk pillowcase?
Wash on a cool, delicate cycle using a gentle detergent, ideally inside a mesh laundry bag, and air dry away from direct heat and sunlight. Avoid bleach, fabric softener and tumble drying, all of which can dull or weaken the fibres over time.
Explore our 19 momme mulberry silk pillowcases
