You have the mattress sorted. Blackout blinds. The magnesium supplements. Room temperature dialled to 18°C. The sleep tracker on the wrist.
And then you take your clothes off and climb into bed.
You might think that if you sleep naked, this does not apply to you. It does.
Your skin is still in contact with something for eight hours. Your sheets. Your duvet cover. Your pillowcase. And usually, all three are made from cotton: the same cotton we are about to explain falls short on the measures that matter most for sleep.
Whether you wear pyjamas, an old cotton t-shirt, or nothing at all, your skin is pressed against some sort of fabric. That fabric is either helping your body do what it needs to do, or it is quietly working against it.
This guide covers what sleepwear is for, how the main fabrics compare, and what to look for.
Why fabric matters for sleep
For you to fall asleep, your core body temperature has to fall. It starts dropping in the evening and falls by around 1°C across the night. This is not preference. It is how your body clock works.
Your body does this through blood moving toward the skin's surface, especially the hands and feet, to release heat. That is why a cool bedroom helps you fall asleep faster. It is also why warming your feet under a duvet counterintuitively helps. It dilates the blood vessels near the skin, speeding the drop in core temperature.
Throughout the night, your body continues to regulate this temperature. You produce sweat. You shed heat. The cycle repeats across every sleep stage.
Your sleepwear sits in the middle of this process. A good fabric gets out of the way. It lets heat escape, moves sweat off your skin, and releases that moisture into the air so you stay dry. A bad fabric traps heat, holds sweat against your skin, and leaves you clammy. That is the difference between deep sleep and another 3am wake-up.
What sleepwear is actually for
Sleepwear has three jobs:
- Thermal management. Let heat escape when you are warm. Retain enough when you are cool. Adapt to shifts across the night.
- Moisture management. Absorb sweat off your skin. Transport it away from the body. Release it to the air.
- Skin comfort. Do not irritate, chafe or pill against the skin over eight hours of contact.
Fail on any of the three and you compromise sleep. Most high-street pyjamas fail on all three.
The fabric decision framework
Here is a simple way to cut through every "best fabric for sleep" listicle on the internet.
Rank candidate fabrics on two things: moisture cycle performance and fibre quality.
Moisture cycle performance is how well a fabric handles the absorb, transport, release cycle. All three stages matter. Cotton absorbs well but releases slowly, so you wake up damp. Polyester transports quickly but traps heat, so you wake up hot. The best fabrics handle all three stages cleanly.
Fibre quality is a proxy for how long the fabric lasts and how comfortable it stays over time. Long, smooth, uniform fibres resist pilling, hold their shape and feel consistent wash after wash. Short, rough or inconsistent fibres degrade fast.
Most sleepwear on the market scores poorly on both. The premium tier (modal, lyocell, silk) scores well on both. The SERIS™ fabric we developed for unsuited is built to score at the top of both, which is the subject of the final section.
Fabrics, ranked
A brief, honest summary. For full detail on each, see Which fabric works best for hot sleepers?
Cotton
The default choice. Affordable, breathable, familiar. It fails on moisture release: once cotton has absorbed your sweat, it holds it against your skin rather than releasing it. Short-staple cotton also pills and thins fast. Long-staple cotton (Pima, Supima) performs better on durability. Neither solves the moisture problem.
Verdict: A reasonable baseline. A poor finisher.
Linen
Exceptionally breathable. Poor at wicking. Coarse until it softens. Good for hot climates, less suited to sleepwear performance.
Verdict: Better for bedding than for what you wear to bed.
Silk
Feels premium. Temperature-responsive to a degree. Expensive, fragile, and comes with a perception problem for most men. Moisture management is more modest than its reputation suggests.
Verdict: Luxurious against the skin. Impractical for most men.
Bamboo viscose
Softer and more breathable than cotton. Marketed as natural. It is not: the finished fabric is chemically processed viscose rayon. Environmental credentials depend heavily on the manufacturer's production process. Moisture release can be sluggish.
Verdict: A step up from cotton, but not the answer for real night sweats.
Lyocell
A cellulosic fibre, typically from eucalyptus wood pulp. Smooth, breathable, handles moisture better than cotton. Produced using closed-loop solvent recovery. A solid, modern choice.
Verdict: A well-rounded performer. Hard to fault.
Polyester and synthetic blends
Sportswear brands have developed impressive moisture-wicking synthetics. These perform well in the gym. They perform badly in bed. They trap heat over long periods of contact and harbour odour-causing bacteria more readily than natural fibres.
Verdict: Wrong tool for the job.
Micro modal air (and specifically SERIS™)
A cellulosic fibre made from beech wood pulp, spun through a specialised process that produces fibres finer than silk. The finest grade of modal, which is what SERIS™ is built on, handles the full moisture cycle cleanly and holds its shape. The most technically capable option for sleepwear.
Verdict: Top of the stack.
Why most men are wearing the wrong thing
Men's sleepwear has been a neglected category for decades.
The mass-market high-street offer is short-staple cotton or poly-cotton blends, built to a price point. These garments can pill within weeks, thin within months and sag out of shape soon after. They are cheap because they are not built to last.
The premium tier that does exist hasn't made inroads. The assumption is that "proper pyjamas" are for a different kind of man: older, more formal, not performance-minded. The category has failed to evolve alongside the men it should be serving.
Meanwhile, the same men are optimising everything else about their sleep. Wearables show the cost of poor sleep in HRV and recovery scores. The sleepwear industry has not caught up.
What a proper sleep fabric looks like
When we built unsuited, we started from the physiology. What does a fabric need to do to support a man's sleep, night after night, wash after wash, for years?
The answer led us to SERIS™.
SERIS™ is our sleepwear fabric, built from the finest grade of modal fibre available. The fibres measure 0.8 decitex, against around 1.0 decitex for standard micro modal and around 1.1 to 1.4 decitex for silk. That makes each fibre finer than silk, smoother and more uniform.
The pulp is sourced from European beech forests, which grow without irrigation or pesticides. Processing happens in a closed-loop system that recovers and recycles the water and chemicals used. The finished fabric is knit and assembled in Portugal with reinforced construction, quality elastic and considered seam placement.
We had SERIS™ tested by SGS, an independent laboratory, against a cotton jersey control. What this means in practice:
- Moisture cycle. SGS classified SERIS™ as a Moisture Management Fabric. It moved moisture away from the skin and through to the outer face. The cotton control did not qualify.
- Airflow. SERIS™ let through 16% more air than cotton: 625 mm/s against 538 mm/s. The ultra-fine fibre structure lets air circulate close to the skin.
- Stretch and recovery. SERIS™ stretched 194% against cotton's 77%, and returned to shape better afterwards rather than sagging.
- Comfort. Finer than silk. A genuine second-skin feel without silk's fragility or price.
The full results are in what the research says about sleepwear fabric.
This is what we put into the Equinox collection. If you track your sleep and treat recovery as a performance metric, your sleepwear should be built to the same standard as the rest of the stack.
Explore the Equinox collection.
Common questions
What is the best fabric for men's sleepwear?
For men who prioritise sleep quality, the finest grade of modal fibre is the strongest overall choice. It handles the full moisture cycle, helps regulate temperature and holds its shape. SERIS™ is built on this fibre grade. Lyocell is a solid alternative at a lower price point. Cotton and bamboo viscose are viable for mild warm sleepers, but fall short for anyone who sleeps hot or sweats at night.
How does fabric affect sleep quality?
Fabric affects sleep in three ways: it regulates heat exchange between your body and the environment, it manages sweat across eight hours of contact, and it determines skin comfort over extended wear. A fabric that fails any of these can cause small disturbances that fragment sleep. A 2024 systematic review in the Journal of Sleep Research concluded that sleepwear and bedding fibres affect sleep by influencing skin temperature and thermal comfort.
Why do I wake up hot at night?
Night-time overheating usually comes from one of three sources: the bedroom is too warm (above about 19°C), your bedding or sleepwear traps heat against the skin, or your body is dealing with something specific, such as alcohol, a late meal or intense exercise within two hours of bed. Fabric is the one most men overlook. For a deeper breakdown, see Which fabric works best for hot sleepers?
Are performance synthetics good for sleepwear?
No. Sportswear synthetics like polyester blends are designed for short bursts of activity, not for eight hours of skin contact. They transport moisture well but trap heat over time, harbour odour-causing bacteria and feel clammy in still air. Hot sleepers often cycle between feeling cool and feeling damp in synthetic sleepwear.
How long should quality sleepwear last?
Standard cotton pyjamas often last only a year or two before pilling, thinning and losing their shape. Higher-quality fabrics like modal and silk can last considerably longer with proper care. The biggest variables are wash temperature, detergent strength and whether you tumble dry. Cold water, gentle detergent and air drying noticeably extend garment life. For the full breakdown, see Why do my pyjamas fall apart?
Do pyjamas actually improve sleep?
Yes, when the fabric is right. Sleepwear sits between your body and the environment and handles the heat and moisture exchange. A fabric that handles this cycle cleanly supports deeper, less fragmented sleep. A fabric that fails at it contributes to the small wake-ups that show up in recovery data. Sleeping naked on cotton sheets, or in a cotton t-shirt, is a suboptimal choice.