What Does 6A Grade Silk Mean for Bed Sheets? | Promeed

Last updated: August 27, 2026 · By: Austin Cole

If you've been researching silk bed sheets, you've likely seen the term “6A grade” or “6A+ mulberry silk” and wondered what it actually means. Is it just marketing language, or does it reflect a real difference in quality? The short answer: it's a genuine grading system, and understanding it can help you avoid paying premium prices for lower-quality silk or polyester imitations. At Promeed, we focus on transparency, so here's what 6A grade silk means for your sleep.

What Is 6A Grade Silk? The Quality Scale Explained

Silk grading starts with the raw silk filament, the continuous thread spun by silkworms (specifically Bombyx mori mulberry silkworms). The grade reflects fiber length, uniformity, cleanliness, and luster. The scale runs from A (lowest) to 6A (highest), though many mills now use a “+” to denote even finer batches. Here's how the grades break down:

• A–2A: Short fibers, irregular thickness, used for filler or low-cost silk blends.
• 3A–4A: Medium quality, acceptable for some apparel but prone to pilling in bedding.
• 5A: Good quality with longer fibers, but still not the longest and most uniform.
• 6A: The top grade — long, fine, uniform filaments that produce a nearly flawless yarn.
• 6A+: A designation used by premium mills for batches with exceptional purity and luster, often exceeding standard 6A parameters. Our 23mm 6A+ Mulberry Silk Bedding collection is made from this grade.

Why does fiber length matter? Longer filaments require fewer joins, so the yarn is stronger and smoother. Short fibers create weak spots that can lead to pilling and a rough feel after washing. With 6A+ silk, the fabric tends to stay silky longer rather than losing its feel after a few washes.

Why 6A+ Mulberry Silk Bed Sheets Are Worth the Investment

Bed sheets are in direct contact with your skin and hair for 7–9 hours every night. That constant friction can contribute to sleep creases, hair breakage, and moisture loss. Lower-grade silk or polyester “satin” cannot replicate the benefits of 6A+ mulberry silk. Here's what the top grade actually delivers for your sleep sanctuary:

• Reduced friction for skin and hair: 6A+ filaments are exceptionally smooth, helping minimize the tugging that can cause fine lines and frizz.
• Temperature regulation: Mulberry silk is naturally thermoregulating. The long-fiber structure allows air to circulate, keeping you cool in summer and cozy in winter — a true year-round luxury.
• Hypoallergenic properties: Silk tends to resist dust mites, mold, and mildew, making it a common choice for those with allergies or sensitive skin. Our 23mm 6A+ silk flat sheet set is OEKO-TEX® Standard 100 certified, meaning it has been tested for harmful substances.
• Durability: A 6A+ sheet set with proper care can hold up significantly longer than polyester satin, which may pill and feel rough after repeated washing. The cost-per-use can make premium silk a practical choice, not just an indulgence.

One thing to note: “mulberry silk” is not automatically 6A. Some brands use 3A or 4A mulberry silk and market it as luxury. Always look for the grade claim from a reputable seller. At Promeed, we specify 6A+ because we believe transparency builds trust.

Momme Weight Explained: Why 23-Momme Makes the Difference

Grade tells you about fiber quality, but momme (pronounced “moe-me”) tells you about fabric density and weight. The higher the momme, the denser and more durable the silk. Typical silk pillowcases are 16–19 momme; luxury sheets range from 19–25 momme. Here's a comparison:

Momme	Feel & Durability	Best For
12–16	Sheer, delicate, prone to wear	Accessories, lingerie
19	Lightweight, soft, but thinner	Pillowcases, summer sheets
22	Balanced weight, decent durability	Everyday bedding
23	Heavyweight, luxurious, long-lasting	Premium sheets (our choice)
25–30	Ultra-heavy, hotel-grade, less breathable for some	Maximum durability

We chose 23-momme for our flagship sheet set because it hits the sweet spot: substantial enough to drape beautifully and resist wear, yet breathable enough for all-season comfort. A 19-momme sheet may feel thinner, while a 30-momme sheet can feel heavy and less breathable for some sleepers. With 23-momme 6A+ silk, you get a balance of weight, softness, and thermal regulation. Learn more about the difference between a flat sheet and fitted sheet in our guide Flat Sheet vs Fitted Sheet: Why You Need Both for Perfect Silk Bedding.

Spotting the Real Deal: 6A+ Silk vs. Imitations

The internet is full of “silk” sheets that are actually polyester satin or low-grade blends. How can you tell if you're getting true 6A+ mulberry silk? Use these checks:

• Check the label: It should say “100% mulberry silk” and specify the grade (6A or 6A+). If it only says “silk” or “satin,” be suspicious.
• Look for certifications: OEKO-TEX® Standard 100 certification means the fabric has been tested for harmful substances. Our set is certified, which is especially helpful if you want to minimize chemical exposure at home.
• Feel the fabric: Real silk warms to your skin within seconds and has a subtle, natural sheen — not a glossy, slick finish. Rub it between your fingers; synthetic satin feels cool and slippery, while silk feels smooth and soft.
• Check the price carefully: A “king silk sheet set” priced under $50 is likely polyester or a low-grade blend. Premium 6A+ mulberry silk costs more to produce, but brands with a direct-to-consumer model can offer it at a fairer price. Our 23mm 6A+ fitted sheet set is a good starting point if you want to try the difference.

Our 23mm 6A+ Mulberry Silk Flat Sheet Set: What's Inside

Our 23mm 6A+ 100% Mulberry Silk Flat Sheets Set 4pcs was designed for the modern professional who wants hotel-quality sleep without the hotel price tag. The 4-piece set includes:

• 1 Flat Sheet: Generously sized to tuck in or drape over. Available in Twin XL (66" x 96"), Queen (90" x 100"), King (108" x 100"), and California King (108" x 104").
• 1 Fitted Sheet: Deep pockets (up to 16") with full elastic to stay securely on your mattress. Sizes: Twin XL (39" x 80"), Queen (60" x 80"), King (76" x 80"), Cal King (72" x 84").
• 2 Pillowcases: Standard size with hidden zipper closures to keep pillows from slipping out.

Every piece is made from 23-momme 6A+ mulberry silk in a range of calming, quiet-luxury shades: champagne, dusk, gold, grey, and white. These neutral tones fit any urban sanctuary aesthetic — no loud logos, just natural fiber. If you prefer an even heavier silk, explore our 30mm 6A+ Mulberry Silk Flat Sheets Set. For a thoughtful gift, consider our 23mm 6A+ Silk Flat Sheets Set Gift Kit, suitable for weddings or housewarmings.

Caring for 6A Grade Silk Sheets: A Simple Routine Reset

If you are refreshing your sleep routine, upgrading to silk sheets is a small change that can noticeably improve comfort. To keep your 6A+ silk sheets feeling their best, follow these care guidelines:

1. Hand wash or machine wash cold on a gentle/delicate cycle using a pH-neutral detergent specifically for silk. Avoid bleach and fabric softeners.
2. Wash separately from rough fabrics and zippers to prevent snags. Use a mesh laundry bag for extra protection.
3. Air dry out of direct sunlight, or tumble dry on low heat for no more than 10 minutes. High heat can damage silk proteins.
4. Iron on low while slightly damp, if needed, using a pressing cloth. Most wrinkles release naturally when the sheets are on the bed.
5. Rotate sets if you can. Having two sets (like our flat sheet set and a fitted sheet set) extends the life of each.

With proper care, high-grade silk tends to soften slightly over time, while lower grades may feel stiff or pill.

Frequently Asked Questions About 6A Grade Silk Bed Sheets

Elevate Your Sleep Sanctuary with 6A+ Silk

Understanding what 6A grade silk means can help you make a more informed purchase — one that prioritizes your skin, hair, and sleep quality while fitting a reasonable budget. Our 23mm 6A+ Mulberry Silk Bedding collection brings high-grade mulberry silk directly to your bedroom without the typical luxury markup. A small upgrade can make mornings feel a little smoother.

References

These sources are included to support the article's material, textile, safety, standards, or claim-verification context.

• OEKO-TEX STANDARD 100 information
• FTC textile and wool labeling guidance
• FTC health claims advertising guidance