Does Mulberry Silk Shrink in the Wash? 23-Momme Care Guide

Worried your silk pillowcase will shrink? With a cold‑wash, air‑dry routine, your 23‑momme mulberry silk stays soft, luminous, and perfectly fitted, wash after wash.

Last updated: June 4, 2026 · By: Adline Keth

In this guide, we break down why 23‑momme mulberry silk is inherently shrink‑resistant, and give you the exact care routine we trust at Promeed.

Price vs. material check

When you’re weighing the cost of a mulberry silk pillowcase, the momme weight tells you most of what you need to know about durability and dimensional stability. A 23-momme pillowcase, like Promeed’s 23-momme pillowcase, packs more silk fiber per square meter than entry-level options, which directly translates to better resistance against abrasion, pilling, and—crucially—shrinkage. This heft is your first line of defense every laundry day.

We've found that 23‑momme mulberry silk preserves its size and softness through dozens of washes when you stick to the right method. Here’s what every busy professional needs to know.

Does Mulberry Silk Really Shrink? The Science of 23-Momme Durability

Silk is a natural protein fiber spun by silkworms. These fibers are similar in structure to human hair, composed of long chains of amino acids. When exposed to excessive heat, harsh chemicals, or aggressive mechanical action, the proteins can denature and contract—leading to shrinkage. However, the degree of shrinkage is heavily dependent on the quality of the silk and the weave. Lower-grade silks, often made from short, broken fibers (known as silk noil or charmeuse with lower momme), are inherently unstable because their molecular structure is less organized. In contrast, Promeed's 23-momme, 6A long-fiber mulberry silk has unbroken, uniform fibers woven into a dense, resilient fabric that resists distortion. Momme weight measures the silk's density: 23 momme is a heavy-weight grade that directly contributes to dimensional stability.

This denser weave provides a stable structure that holds its shape through washing. So while a thin silk might easily pucker or shrink, a robust 23-momme piece largely maintains its original dimensions—provided you follow a few simple care steps. That’s precisely the confidence you get with the 23mm 6A+ 100% Mulberry Silk Pillowcase With Zipper With Laundry Bag. And because we use only 6A grade silk and craft every pillowcase with OEKO-TEX® certified materials, you can trust it’s free from harmful substances and physically stable, right from the first night.

How to Wash Your Silk Pillowcase Without Fear

With the right technique, you can wash your silk pillowcase confidently, even in a shared city apartment washer. Here’s the exact method we recommend—and that we personally use at Promeed HQ.

Step-by-Step Washing Routine

1. Preparation: Zip up the hidden zipper completely (if your pillowcase has one) and turn the pillowcase inside out. This shields the smooth face of the silk from any stray snags inside the machine.
2. Bag It: Place the pillowcase into the mesh laundry bag that came with your order. Pull the drawstring tight and tuck it inside. For best results, wash only one or two silk items per bag to allow free movement and thorough cleaning. If you own our 23mm 6A+ Zipper Mulberry Silk Pillowcases 2 Pack, you can keep one fresh on your bed while the other cleans.
3. Select a Detergent: Reach for a pH-neutral, silk-safe detergent. Avoid mainstream laundry detergents that often contain enzymes, brighteners, or bleaching agents. A small amount of delicate wash or even a few drops of baby shampoo work perfectly. Skip fabric softener—it can leave a coating on the fibers, diminishing the silk's natural feel.
4. Machine Washing: Set your washing machine to the delicate or hand-wash cycle, with cold water (86°F/30°C max) and the lowest spin speed. If your machine has an extra-rinse option, use it to ensure all detergent is flushed out. Never wash your silk with heavy items like jeans or towels.
5. Hand Washing (Optional): If you have a few extra minutes, hand washing is the gentlest method. Fill a clean basin with cool water, add detergent, and submerge the pillowcase in its bag. Gently agitate for 2–3 minutes, then drain and rinse with cool water until it runs clear. Do not wring or twist—simply press out the water with a clean towel.

Machine Wash vs. Hand Wash: A Quick Comparison

Machine Wash	Hand Wash
Uses delicate cycle, cold water, and protective laundry bag.	Gently agitated by hand in cool water with mild detergent.
Ideal for busy professionals; set and forget.	Best when you have time and want maximum gentleness.
Air drying afterward is essential.	Roll in towel and air dry flat.

The Included Laundry Bag: Your Key to Protection

We don’t just include a laundry bag because it’s nice to have—it’s a key part of silk care. Friction from the washing machine’s drum and from other clothes is a primary culprit when silk shrinks or pills. The bag acts like a protective layer, absorbing the agitation while letting water and detergent circulate freely. It’s especially crucial in urban living situations where most of us share laundry facilities: you never know what residue or roughness was left behind from the previous load. Simply zip your pillowcase up and rest easy. The 23mm 6A+ 100% Mulberry Silk Pillowcase With Zipper With Laundry Bag comes with this essential accessory so you can wash without second-guessing.

Drying: How to Avoid Shrinkage

Drying is where many well-intentioned silk lovers go wrong. Even a single tumble on low heat can cause permanent shrinkage, so commit this rule to memory: air dry only.

• Lay flat: Place the pillowcase on a dry, clean towel, roll it up to absorb moisture, then unroll and transfer it to a mesh drying rack or another dry towel. The goal is to support the fabric’s full weight so it doesn’t stretch under its own damp heaviness.
• No direct heat: Avoid radiators, heating vents, and direct sunlight. While a little indirect sun is fine, prolonged UV exposure can weaken the fibers, potentially affecting the fabric's size and feel.
• Ironing (if needed): If creases bother you, use a cool iron (silk setting) and always place a pressing cloth—a clean cotton pillowcase works well—between the iron and the silk. Even better, smooth the pillowcase with your hands while it dries; 23-momme silk’s natural weight often allows wrinkles to release on their own.

Proper drying technique is as important as washing; following these steps keeps your silk pillowcase in the same shape as the day you received it.

City Living, Hard Water, and Your Silk

Your urban environment presents unique challenges for silk. Hard water—common in many metro areas—contains minerals like calcium and magnesium that can build up on silk fibers over time, making them feel stiff and possibly contributing to gradual shrinkage if not rinsed thoroughly. We recommend using cold water and the extra-rinse cycle if your machine has one. If you’re hand washing, a final rinse with distilled or filtered water can work wonders. To keep your routine foolproof, protect your investment with our 23mm silk pillowcase 3‑pack with protective laundry bags, which ensures clean results even in high-rise laundry rooms.

City air also carries pollution particles that settle on your pillowcase during the night, mixing with your skincare products and sweat. Regular washing (once a week is ideal) not only prevents that buildup but also ensures your skin rests against a clean, hypoallergenic surface. Because Promeed silk is OEKO-TEX® certified and naturally dust-mite resistant, it offers a cleaner sleep environment than many synthetics, but the weekly wash keeps it truly pristine.

Smart Luxury That’s Built to Last

At Promeed, we understand that our customers—busy professionals, entrepreneurs, and creatives—don’t have hours to devote to hand-washing. Yet they still deserve the skin, hair, and sleep benefits of premium silk. So we created a 23-momme mulberry silk pillowcase that balances easy care with luxury feel.

Our pillowcase has been recognized by Good Housekeeping, a testament to its quality and durability. Many customers report that they were hesitant about washing silk, but after using our laundry bag and delicate cycle, they find their pillowcases stay beautiful through dozens of washes. If you’re comparing brands, you’ll notice that Promeed delivers 6A silk quality and 23-momme density at a more accessible price than many high-end names. And because we believe in smart rotation, our 23mm 6A+ mulberry silk pillowcase 3‑pack is built to last through hundreds of washes, ensuring you always have a fresh, shrink-free pillowcase ready.

Beyond Washing: How to Store Your Silk Pillowcase to Retain Its Shape

Proper storage is just as important as washing for preventing shrinkage and deformation. Never hang your silk pillowcase on a hook or hanger, as the weight of the fabric can stretch the fibers over time. Instead, fold it loosely and store it in a breathable cotton or linen bag—avoid plastic, which can trap moisture and lead to mildew. The included mesh laundry bag also doubles as a storage sack: simply slip the clean, dry pillowcase inside and place it on a shelf. This maintains its shape and protects it from dust. If you rotate between pillowcases to extend the life of each, our 23mm 6A+ Zipper Mulberry Silk Pillowcases 2 Pack makes it effortless to always have a fresh one on hand.

Single Pillowcase or Multi-Pack: Which is Right for You?

If you're ready to commit to nightly silk, a multi-pack offers practical advantages. Below, see how our single pillowcase and 2-pack compare so you can choose what fits your routine.

Frequently Asked Questions

Wash with Confidence

To circle back to the original question: does mulberry silk shrink in the wash? Not when you pair high-density 23-momme silk with a thoughtful laundering routine. The takeaway is simple: Promeed’s silk is built to last, and our included laundry bag makes preservation effortless. So go ahead, wash your pillowcase as often as needed to keep it fresh and hygienic—every week, even. For a ready rotation that makes weekly washing effortless, grab the 23mm 6A+ Mulberry Silk Pillowcase With Zipper 3 Pack. Your skin and hair will thank you.

Ready to elevate your nightly ritual? Explore the full range of 23mm 6A+ Mulberry Silk Pillowcases and choose from over ten shades to match your urban oasis. For the complete system, shop the 23mm silk pillowcase with laundry bag.

Discover the 23mm Silk Pillowcase with Laundry Bag

References

• Federal Trade Commission. (n.d.). Threading Your Way Through the Labeling Requirements Under the Textile and Wool Acts. FTC.gov — Guidance that helps consumers understand textile fiber names and fabric labeling, relevant for identifying genuine mulberry silk.
• OEKO-TEX. (n.d.). OEKO-TEX STANDARD 100. OEKO-TEX.com — Information about the certification for textile safety, referenced in Promeed's use of OEKO-TEX certified materials.

Next step

When the fit feels clear, use the next step below to review the most relevant Promeed option.

See the recommended 23mm 6A+ Zipper Mulberry Silk Pillowcases 2 Pack Mixed Colors