What Does Momme Mean?
Momme (pronounced “moh-mee” and abbreviated as “mm”) is the traditional Japanese unit used to measure the weight and density of silk fabric. Technically, one momme equals the weight in pounds of a piece of silk measuring 45 inches by 100 yards. This measurement standard, established by the International Silk Association, provides a reliable and verifiable indicator of silk fabric density. But you do not need to remember that formula.
What matters is this: higher momme = denser, more durable, more luxurious silk. Think of momme as a quality indicator. A 19mm silk feels noticeably thinner and less substantial than a 23mm silk. A 25mm silk feels dense and opaque. Each step up in momme brings a tangible improvement in feel, durability, and performance.
Unlike thread count, which can be inflated with multi-ply yarns and creative counting, momme weight is straightforward and hard to fake. When a silk product says 23mm, that is a measurable, verifiable claim about the density of the fabric.
Why Momme Count Matters
Momme count directly affects three things you care about as a consumer:
Momme Weight Comparison Chart
Here is how different momme weights compare across the key factors that matter for bedding:
| Weight | Category | Durability | Feel | Best For | Price |
|---|---|---|---|---|---|
| 16mm | Lightweight | Low | Thin, breezy | Scarves, linings | $ |
| 19mm | Mid-weight | Moderate | Smooth, slightly thin | Budget pillowcases | $$ |
| 22mm | Standard luxury | Good | Luxurious, balanced | Pillowcases, eye masks | $$$ |
| 25mm | Heavyweight | Excellent | Dense, substantial | Sheets, duvet covers | $$$$ |
Why 23mm Is the Sweet Spot
After testing silk pillowcases at every momme weight from 16mm to 30mm over a combined 200+ nights of use, we consistently recommend 23mm as the optimal weight for silk bedding. Here is why:
- Better than 22mm on durability. The extra momme translates to a noticeably more durable fabric that holds up better wash after wash. In our testing, 23mm silk maintained its luster and smoothness significantly longer than 22mm.
- Not as heavy as 25mm. While 25mm silk is incredibly durable, it can feel too dense and heavy for some sleepers, especially in warmer climates. It also costs considerably more. At 23mm, you get excellent density without the heaviness.
- Optimal temperature regulation. The 23mm weight strikes the perfect balance for breathability and insulation. It is dense enough to provide gentle warmth in winter but breathable enough to stay cool in summer.
- Best value proposition. At 23mm, you get near-premium quality at a price point that is often lower than competing 22mm products from luxury brands. This is especially true with brands like Promeed, which offers 23mm 6A+ silk at prices lower than Blissy and Slip's 22mm offerings.
Momme Count vs. Thread Count
If you are coming from the cotton world, you might wonder how momme relates to thread count. The short answer: they measure different things and are not directly comparable.
Thread count measures the number of threads per square inch of fabric. It works well for cotton because cotton threads are relatively uniform. However, thread count has been heavily gamed by manufacturers who use multi-ply yarns to inflate numbers, making a 200-thread-count sheet technically label as 400 or 600.
Momme, by contrast, is a weight-based measurement that is nearly impossible to inflate. This makes it a much more reliable quality indicator. When you see 23mm on a silk product, you know exactly what you are getting, regardless of the brand.
As a rough comparison: a 19mm silk is approximately equivalent in feel to a 400-thread-count cotton, while a 23mm silk compares favorably to an 800+ thread count cotton in terms of smoothness and luxury feel. But the silk also adds temperature regulation, hypoallergenic properties, and skin benefits that cotton simply cannot match.
How to Verify Momme Count
Reputable silk brands always list the momme weight prominently. If a product does not mention momme count, treat it as a red flag. Here are some tips for verifying quality:
- 1.Check the product listing for specific momme weight (not just “high quality silk”).
- 2.Look for the silk grade alongside momme (6A is the highest commercially available grade).
- 3.Check for OEKO-TEX or similar certifications that verify material claims.
- 4.Feel the fabric: higher momme silk feels denser and more substantial, with a beautiful drape.