Real Silk Guide: 10 Ways to Know

How to Tell if Silk Is Real (and Not Polyester Satin)

Shopping for “silk” can be confusing. Many products labeled “silky,” “satin,” or even “silk” are actually polyester or rayon. Use this simple guide to spot genuine mulberry silk and avoid imitations.

Quick Checklist

  • Feel: real silk is cool to the touch, then warms quickly.

  • Sheen: soft, two-tone glow that shifts with the light (not mirror-shiny).

  • Texture: smooth but not slippery; tiny natural irregularities.

  • Sound: a gentle “silk rustle” when rubbed, not plastic swish.

  • Static: minimal static and cling.

  • Label: look for Grade 6A mulberry silk, momme (mm) weight (19–25 mm is premium), and OEKO-TEX® certification.

  • Price: authentic silk isn’t ultra-cheap—be cautious of heavy discounts.

What “Real Silk” Means

Real silk is a natural protein fiber spun by silkworms. The most coveted type for bedding and pillowcases is mulberry silk, graded by fiber quality (A–C, with 6A the highest) and fabric weight (momme/mm).

  • Momme (mm): A measure of density. Around 22–25 mm offers a great balance of durability, drape, and luxury for pillowcases.

  • Charmeuse weave: Smooth, lustrous face and a softer matte back—common in high-quality silk pillowcases.

10 Proven Ways to Identify Real Silk

  1. Temperature Test
    Touch the fabric: real silk feels cool at first, then warms to your skin. Synthetics often feel room-temperature or quickly clammy.

  2. Luster (Sheen) Check
    Move it under light. Silk shows a soft, deep luster with subtle color shifts; polyester looks uniformly shiny and glassy.

  3. Texture & Handfeel
    Silk is buttery smooth but not overly slippery. Under your fingers you may sense micro-texture from the natural fibers—imitations feel either squeaky or overly slick.

  4. The Rustle
    Rub two layers gently. Real silk makes a delicate, crisp rustle. Polyester makes a dull swish.

  5. Wrinkle Test
    Squeeze and release. Silk shows light, temporary creases that relax quickly. Polyester often springs back with no creasing or holds stiff wrinkles.

  6. Static & Cling
    Silk is naturally low-static. If it clings strongly or sparks easily, it’s likely synthetic.

  7. Weave & Edge Inspection
    Look closely at seams and edges. Premium silk shows fine, even stitching, consistent weave, and less fraying than cheap satins.

  8. Absorbency Drop Test
    Place a tiny water drop on an inconspicuous area. Silk absorbs slowly and darkens slightly; polyester tends to bead on the surface.

  9. Label & Certifications
    Trust labels that state “100% mulberry silk,” grade (e.g., 6A), and momme weight. OEKO-TEX® Standard 100 means the fabric is tested for harmful substances.

  10. Price & Claims
    If it’s sold as “satin” without saying “silk,” it’s usually polyester satin (satin is a weave, not a fiber). Be cautious of “silk-feel,” “silky,” or “blended” claims without clear fiber content.

⚠️ Note on Burn Tests: Some blogs suggest burning a thread (silk smells like burnt hair, ash crushes easily). We don’t recommend DIY burning for safety and because finishes can affect results.

Silk vs. Satin vs. Polyester: What’s the Difference?

  • Silk: Natural fiber; breathable, temperature-regulating, low-static; helps reduce hair friction, frizz, and sleep creases.

  • Satin (as a term): A weave, not a fiber. “Polyester satin” looks shiny but lacks silk’s breathability and skin-friendly properties.

  • Polyester: Synthetic; tends to trap heat and create static; shiny surface can look plasticky.

How to Read a Silk Pillowcase Listing

  • Both sides silk: Ensure it’s genuine silk on both sides, not “one-sided silk” or “silk front, polyester back.”

  • Momme weight: For everyday luxury and durability, look for 22–25 momme.

  • Fiber grade: 6A mulberry silk is top quality.

  • Closure & finish: Hidden zipper or secure envelope closure; double-stitched seams; OEKO-TEX® certification.

  • Care: Delicate cycle 30°C, silk-safe detergent, air-dry, light iron on low.

FAQs

Is satin the same as silk?
No. Satin is a weave pattern. It can be woven from silk (silk satin) or synthetics (polyester satin). Most “satin” pillowcases on the market are polyester, not silk.

What momme should I choose?
For pillowcases, 22–25 mm offers excellent durability and a luxury handfeel. Lower momme (e.g., 16–19) is lighter and may wear faster.

What does Grade 6A mean?
It’s the highest fiber grade for mulberry silk—longer, stronger, more uniform filaments for a smoother, more durable fabric.

Why does silk help hair and skin?
Silk’s ultra-smooth surface reduces friction (less breakage and frizz) and doesn’t wick moisture like cotton, helping skin retain hydration and reducing sleep creases.

How do I care for real silk?
Wash on delicate at 30°C (or hand-wash) with a silk-safe detergent. Air-dry; avoid tumble dryers. Iron on low if needed.

GlowinSleep’s Promise (Optional section for your brand)

  • 100% mulberry silk, Grade 6A, 22 momme charmeuse (both sides)

  • OEKO-TEX® Standard 100 certified

  • Thoughtful finishes: hidden zipper, double-stitched seams, gift-ready packaging

Ready to feel the difference of real silk? Explore GlowinSleep’s silk pillowcases.