Frequently Asked Questions | ZILK Sleep
The Science of Silk
What is ZILK?
ZILK Sleep is a sleep and wellness brand founded by Elizabeth Cook, a board-certified Physician Assistant. Each product is made from 25-momme mulberry silk infused with SILVADUR silver-ion technology to support cleaner skin, smoother hair and more restorative rest.
What are ZILK products made from?
Every ZILK piece is made from 100% 6A-grade mulberry silk with a dense 25-momme weave. Each fiber is treated with SILVADUR silver-ion technology from DuPont, which helps resist odor-causing bacteria. All products are certified to Oeko-TEX Standard 100 and bluesign standards.
What is SILVADUR™ silver-ion technology?
SILVADUR is a patented smart-release system developed by DuPont. It bonds silver ions directly to silk fibers to help resist odor-causing bacteria and maintain freshness through many washes, without affecting softness or breathability.
Are silver ions safe?
Yes. SILVADUR technology is certified to Oeko-TEX Standard 100 and bluesign standards. It is clinically tested to be non-irritating and non-sensitizing. Silver ions are bonded at the fiber level and will not wash away into waterways.
Will silver-ion protection last forever?
Textiles naturally change with use, but SILVADUR technology is engineered for durable performance. Lab testing confirms greater than 99.9% bacterial resistance after 50 washes when cared for as directed.
Benefits + Results
What are the benefits of sleeping on silk?
Silk reduces friction and absorbs less moisture than cotton, helping preserve skin hydration and limit hair frizz and breakage. ZILK's SILVADUR silver-ion infusion adds a layer of freshness by helping resist odor-causing bacteria on the sleep surface.
Does ZILK silk help with acne or irritation?
Silk's smooth, low-friction surface is gentler on reactive skin than cotton. SILVADUR silver-ion technology helps resist bacteria on the fabric surface, supporting a cleaner sleep environment over time.
Is silk better for hair?
Yes. Silk's low-friction surface reduces mechanical stress on hair during sleep, helping limit tangles, frizz and breakage while preserving moisture and styling.
Does ZILK silk help regulate temperature?
Silk is a naturally thermoregulating fiber. It adapts to body temperature, helping keep you cool in warmer conditions and comfortable when it is cooler.
Care + Maintenance
How should I wash my ZILK silk?
Hand wash in cold or lukewarm water with a pH-neutral silk detergent. Or machine wash on a delicate or silk cycle in a mesh laundry bag with like colors. Avoid bleach and fabric softeners. Air dry flat or on a rack away from direct sunlight.
Can I machine wash ZILK silk?
Yes. Use a mesh laundry bag, select a delicate or silk cycle with cold water and a pH-neutral detergent. Hand washing is recommended for smaller items such as sleep masks and scrunchies to preserve their shape.
Can I tumble dry silk?
No. High heat damages silk fibers and reduces performance. Gently press out excess water with a towel and air dry naturally.
Can I iron or steam silk?
Yes. Use a low heat setting while the fabric is slightly damp, or use a handheld steamer. Turn the item inside out or use a pressing cloth for protection.
How often should I wash my pillowcase?
Every 7 to 10 days is typical. SILVADUR silver-ion technology helps resist bacteria between washes, keeping the sleep surface fresher for longer than untreated fabrics.
Orders + Shipping
Where does ZILK ship from?
EU orders ship from the Netherlands.
Do you ship internationally?
We currently ship within the EU. Additional regions are coming soon.
What is your return policy?
We accept returns within 60 days of delivery. Items must be unused, unwashed and in their original packaging with all tags intact. To start a return, email support@zilksleep.com with your order number. Once approved, we will send a prepaid return label and instructions. A return shipping fee of €8 will be deducted from your refund. A 15% restocking fee may be applied.
How long do refunds take?
Refunds are typically processed within 5 to 7 business days of receiving your return.
Brand + Sustainability
Who founded ZILK?
ZILK Sleep was founded by Elizabeth Cook, a board-certified Physician Assistant and international aesthetic expert. Elizabeth built the brand on the belief that sleep is one of the most effective and underused tools in skin and hair health.
What does “Science of Silk. Ritual of Restoration.” mean?
It is our brand promise: combining verified silk science with intentional design to support skin, hair and rest.
Is ZILK sustainable?
Yes. All ZILK products are cruelty-free and produced by partners who meet strict labor and environmental standards.
Is ZILK cruelty-free?
Yes. All ZILK products are cruelty-free and ethically produced by partners who meet strict labor and environmental standards.
Still have questions?
Email us at support@zilksleep.com or follow @zilksleep for silk science and sleep wellness content.
