Sleepout® fabric is a proprietary synthetic, polyester-based weave. The sewn-in label reads “100% polyester.” It combines full blackout performance, durability, portability, and low chemical emissions.
100% blackout
Sleepout fabric blocks 100% of light—not “mostly” or “almost.” It can make a room dark during the day, helping cue the body to rest and making it easier to fall asleep and stay asleep.
Thermal and noise insulation
The dense fabric provides thermal insulation, helping keep a room cooler in summer and warmer in winter. It also dampens outside noise for a quieter sleep environment. Although blackout fabrics can absorb heat, Sleepout curtains use an HOA-approved white backing that reflects sunlight rather than absorbing it.
Feel, durability, portability, and care
The fabric is softer than stiff or plastic-feeling blackout materials and is designed for durability. It is lightweight, foldable, machine-washable, and suitable for travel, hotels, or anywhere you need a dark sleep space. It works with Sleepout curtain products, including Sleepout Portable.
Material and safety rationale
Sleepout chose a proprietary polyester-based weave to avoid harmful treatments and chemical residues while maintaining blackout performance and durability.
Cotton, linen, and other “natural” curtain fabrics can require processing such as:
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Formaldehyde-based resins for wrinkle resistance and shape retention
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Plastic-based coatings to stabilize fibers
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Sterilization chemicals during finishing
A “100% cotton” label may not account for synthetic additives, and some natural-fiber curtains fail standards such as GREENGUARD Gold because of formaldehyde and other toxins. Sleepout's polyester construction is the only approach the company found that met its safety and performance goals.
Certifications and chemical safety
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Sleepout fabric is lab-tested, certified non-toxic, and hypoallergenic.
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It is OEKO-TEX® Standard 100 certified at Class I, meaning it has been tested for harmful substances and is safe for babies and sensitive individuals.
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It is the world's only blackout fabric with that OEKO-TEX® certification and was the first blackout fabric to meet the standard.
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Sleepout curtains are the world's only blackout curtains certified GREENGUARD Gold by UL.
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Sleepout owns the GREENGUARD Gold certification. The exact fabric customers receive—not merely a similar material—has been tested for more than 15,000 volatile organic compounds (VOCs).
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GREENGUARD Gold certification indicates low chemical emissions and suitability for indoor environments.
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Sleepout fabric is completely free of formaldehyde and is the world's only blackout fabric to make that claim.
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Its polyester-based synthetic blend avoids the dangerous formaldehyde levels found in other curtains.
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While heat can cause other blackout fabrics to off-gas harmful chemicals, Sleepout curtains are designed to remain safe in direct sunlight without releasing dangerous fumes into the sleep space.