If you've been researching silk pillowcases or sleep masks, you've probably seen the term Grade 6A silk — and wondered what it actually means. Most brands use the phrase without explaining it. This post breaks down the entire silk grading system so you know exactly what you're buying and why grade matters more than almost any other factor.
What Is the Silk Grading System?
Silk is graded based on the quality of the raw filament — specifically its length, uniformity, cleanliness, and the absence of defects. The grading scale runs from Grade A (the lowest acceptable quality) through Grade 6A (the highest available).
- Grade A — Short, uneven filaments with visible imperfections. Often used in lower-cost products or blended fabrics. Rough texture, poor durability.
- Grade 2A / 3A — Longer filaments with fewer defects. Smoother than Grade A but still inconsistent. Common in mid-range products.
- Grade 4A / 5A — High quality. Long, uniform filaments with minimal imperfections. Used in premium silk products. Noticeably softer and more durable than lower grades.
- Grade 6A — The highest grade. The longest, most uniform filaments available, with virtually no defects. The smoothest surface, the most consistent weave, and the greatest durability. Used in the finest silk bedding and accessories in the world.
What Does Grade Actually Affect?
1. Texture and Smoothness
Higher-grade silk has longer, more uniform filaments that lie flat and parallel in the weave. This creates a surface that is genuinely smooth — not just smooth-looking. Lower-grade silk has shorter, irregular filaments that create micro-roughness even when woven tightly. That roughness is what causes friction on skin and hair.
For a pillowcase or sleep mask, this matters enormously. The friction-reducing benefits of silk — fewer sleep lines, less hair breakage, better lash retention — depend on the surface being genuinely smooth. Grade 6A delivers that. Lower grades approximate it.
2. Durability
Longer filaments mean fewer joins in the weave, which means fewer weak points. Grade 6A silk holds up to nightly use and regular washing far better than lower grades. A Grade A or 2A pillowcase may feel acceptable when new but degrades noticeably within months. Grade 6A at 22 momme maintains its texture and performance for years.
3. Consistency
Lower-grade silk is more variable — you might get a good batch or a poor one. Grade 6A is tightly controlled. The filament length, diameter, and cleanliness meet strict standards at every production run. That consistency is what allows brands to make reliable claims about performance.
Grade vs Momme: What's the Difference?
- Grade = the quality of the silk fiber itself (filament length, uniformity, defects)
- Momme (mm) = the weight and density of the woven fabric (how much silk per unit area)
You need both to be high for a truly premium product. A high-grade silk woven at low momme will be too thin and delicate. A high momme weight made from low-grade silk will be dense but rough. The combination of Grade 6A + 22 momme is the benchmark for luxury silk sleep products. Read our full guide on momme weight: 22 Momme vs 19 Momme Silk: What's the Difference?
Why Most Brands Don't List Their Silk Grade
Because they're not using Grade 6A. Silk grading is not regulated by a single international body, which means brands can use the term loosely — or not mention grade at all. If a brand doesn't list the grade, it's almost always because the grade is lower than 6A and they'd rather not draw attention to it.
Brands that use Grade 6A list it prominently because it's a genuine differentiator. It costs more to source, it's harder to produce consistently, and it results in a meaningfully better product.
Why Soreia Uses Grade 6A
Every Soreia product — pillowcases, sleep masks, bonnets, and scrunchies — is made from Grade 6A, 22 momme OEKO-TEX® certified mulberry silk. We use Grade 6A because the benefits of silk that we promise — reduced friction, better skin hydration, less hair breakage, temperature regulation — are only fully delivered at this grade.
OEKO-TEX® certification adds an additional layer of assurance: our silk has been independently tested and verified to be free from harmful substances. Learn more: What Is OEKO-TEX Certification and Why It Matters.
Soreia doesn't have tens of thousands of reviews. We don't manufacture in volume to hit a price point or run incentive programs to inflate ratings. What we have is a specification we're willing to put our name on — and customers who noticed the difference and came back. When you're evaluating any silk brand, ask for the grade, the momme weight, and the certification. We answer all three without hesitation. Trust is built on transparency. Ours is in the specification.
How to Verify Silk Quality Before You Buy
- ✅ Grade 6A listed explicitly
- ✅ 100% mulberry silk (not "silk blend" or just "satin" — see Silk vs Satin: What's Actually the Difference?)
- ✅ 22 momme weight (19–25 momme is acceptable; 22 is optimal for pillowcases and masks)
- ✅ OEKO-TEX certified — independently verified, not self-declared
- ✅ Clear return policy — brands confident in their quality stand behind it
If any of these are missing, ask the brand directly. A reputable silk brand will answer without hesitation.
Shop Grade 6A Silk
Every Soreia product meets all five criteria above. Browse our full range:
→ Silk Pillowcase Collection — Grade 6A, 22 momme, OEKO-TEX certified
→ Silk Sleep Mask — Contoured, zero eye pressure, Grade 6A silk
→ Read our FAQ — more answers about our silk sourcing, certifications, and care
Also worth reading: How to Build a Complete Silk Sleep Ritual.
Written by the Soreia Beauty Team — specialists in luxury silk sleep accessories.
