Momme: What the Silk Weight Means and Which Number to Look For
Buy silk and sooner or later you meet a figure like “19 momme” or “22 momme”. It sits right next to the product name and is rarely explained, yet it is one of the most telling specs a silk product carries: in short, a measure of how heavy the fabric is. This guide covers what momme means, how it converts to grams, why silk is measured by weight rather than thread count, and which number makes sense for what.
What does momme mean?
Momme (mm) is how the weight of a silk fabric is measured. The unit comes from Japan, and it sets a figure for how much silk sits in a given area. In practice, one rule of thumb is enough: 1 momme equals roughly 4.34 grams per square metre. A fabric at 22 momme therefore weighs about 95 grams per square metre.
The higher the momme, the more silk fibre sits in the same area. The fabric is either more densely woven or made from heavier threads; it hangs with a heavier drape and feels more substantial. A low number means a lighter, more sheer material.
Why weight instead of thread count?
For cotton bedding, thread count, the number of threads per square inch, is the usual quality figure. Silk settled on weight instead, and for a good reason: silk threads are so fine that a raw thread count tells you little. Fabric weight captures both things at once: the fineness of the threads and the density of the weave. Momme and grade then describe two different things: momme is about the fabric, while the raw-silk grade, such as 6A, is about the quality of the fibre itself. We cover what lies behind that grading in our guide to mulberry silk.
Which momme for what?
There is no official standard, but there is a settled trade convention you can use as a guide:
| Momme | Character | Typical use |
|---|---|---|
| under 16 | light, fluid, sometimes sheer | scarves, linings |
| 16 to 19 | light to medium weight | blouses, light bedding |
| 19 to 25 | dense and opaque, substantial in the hand | pillowcases, bedding, bonnet linings |
| over 25 | heavy and very dense | heavy bedding, curtains |
For silk pillowcases, 19 to 25 momme is the usual quality range. Within it, 22 momme has become the established standard: heavy enough to sit opaque and feel dense in the hand, while staying soft and flowing rather than stiff.
Is more momme always better?
No, and this point often gets lost in the marketing. The momme figure describes the fabric, not the quality of the fibre. A high-momme fabric woven from low-grade, short-fibre silk is still a low-grade product. A very high momme also has practical downsides: the fabric gets heavier, warmer, and noticeably more expensive, without the everyday benefit rising to match.
Momme only means something read alongside the rest: the fibre (mulberry silk), the raw-silk grade (6A as the top of the long-fibre scale), and the weave (usually a satin weave). If a silk product states no momme at all, that is not automatically a bad sign, but it is worth asking about.
Momme at RENESSY
The pillowcases in our silk pillowcase collection sit at 22 momme: 100% organic mulberry silk, Grade 6A, woven with silk on both faces instead of a silk front over a cotton or synthetic backing. The certification is there to be checked, GOTS for the organic fibre and the OEKO-TEX MADE IN GREEN label, and Dermatest has skin-tested and certified them, sensitive skin included. Keeping silk at its best is covered in our guide on how to wash silk.
Frequently asked questions
How much does 22 momme silk weigh?
About 95 grams per square metre, following the rule of thumb that 1 momme is roughly 4.34 g/m². For comparison: 19 momme is about 82 g/m², and 25 momme about 109 g/m².
Where does the momme unit come from?
From Japan, where momme (匁) is a traditional unit of weight. Through the historic silk trade it became the international measure for silk fabric, and it is still used worldwide today.
Is momme enough to judge quality?
No. It is an important piece, but it says nothing about the quality of the fibre. Alongside it, check the fibre statement (“100% silk”, ideally mulberry silk), the raw-silk grade, and any certifications.