Silk vs Cotton vs Down: Which Duvet Is Best for You?

The short answer: Down is the warmest for its weight and suits cold sleepers in cooler rooms. Silk is the most breathable and suits warm sleepers and well heated homes, staying comfortable across seasons. Cotton is affordable and easy to wash, but heavier and quicker to flatten. The best duvet is the one that matches how warm you sleep and how warm your bedroom is.

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Ask three friends what they sleep under and you will probably get three firm opinions. One swears by the cloud of a down duvet. One has never thought about it. And one, usually the person who wakes at 3am kicking off the covers, has quietly switched to silk.

They can all be right. A duvet is not a status symbol; it is a small climate system you climb into every night. The question is not which material is "best", but which one is best for you.

So let us be honest with you, even though we make silk duvets.

What Does Your Duvet Actually Do While You Sleep?

Your body does not stay at one temperature through the night. As you fall asleep, your core temperature drops, and it rises again towards morning. Your duvet's job is to support that rhythm, not fight it.

Sleep researchers describe the pocket of air between your skin and your bedding as the bed climate. Studies suggest we sleep best when it sits around 32 to 34°C with 40 to 60% humidity¹. Too hot or too humid, and the body spends more time awake and less time in deep and REM sleep.

That gives us two things to judge any duvet by:

• Warmth: how well it holds in heat.

• Breathability: how well it lets excess heat and moisture escape.

Every fill strikes a different balance between the two.

Down Duvets: The Warmest for Their Weight

Down is the soft cluster that grows beneath a goose or duck's outer feathers. Each cluster traps a remarkable amount of still air, which is what makes down the most efficient insulator of the three. Its quality is measured in fill power: the higher the number, the more loft (and warmth) each gram provides.

What it does well: exceptional warmth with very little weight, that classic lofty "cloud" feel, and a long life when cared for well. Down duvets have long been a staple of Swiss bedrooms for good reason.

Where it falls short: all that trapped air can become too much for warm sleepers, particularly in a well heated apartment. Down is also lofty rather than draping, so it sits on top of you more than it settles around you.

A note on allergies: true allergy to down itself is relatively uncommon. Most bedding related allergies are caused by dust mites, and one study even found more mite allergen in synthetic pillows than in feather ones². Well processed down in a tightly woven casing suits many allergy sufferers. If you choose down, look for responsibly sourced fill, such as down certified to the Responsible Down Standard (RDS).

Cotton Duvets: Simple, Washable, Familiar

A cotton duvet is filled with cotton wadding rather than down or silk. (Not to be confused with a down duvet in a cotton casing, which is very common.)

What it does well: cotton is a plant fibre, it is usually easy to wash, and it tends to be the most affordable natural option. As we explored in What Does 100s Cotton Mean?, cotton fibres naturally take up moisture, which helps it feel dry against the skin.

Where it falls short: cotton fill is noticeably heavier for the same warmth, and over time it compacts, losing loft and leaving thinner patches. It also holds on to moisture longer than silk or down, so on a warm night it can begin to feel damp and heavy.

Silk Duvets: The Breathable One

A silk duvet is filled with long, continuous silk filaments, layered into a light, even sheet. Rather than trapping a thick layer of air like down, silk drapes close to the body and lets heat and moisture move through it.

What it does well: breathability is silk's great strength, which helps keep the bed climate steady instead of letting heat build up. It drapes softly around you, it is light, and it contains no feather proteins, which many sensitive sleepers appreciate. For warm sleepers and well heated homes, it is often the duvet that finally ends the 3am cover kick.

Where it falls short: silk is not as lofty as down, so if you love sinking into a puffy cloud, it will feel different. Very cold sleepers in cool rooms may prefer a heavier weight or a down duvet. Silk also asks for gentle care: most silk fills should not go into a washing machine, so always follow the care label.

Silk vs Cotton vs Down at a Glance

A general guide. Construction, fill quality and weight make a real difference within each type.

So Which Duvet Is Best for You?

• You run warm, or wake up hot: choose silk. Its breathability is exactly what a warm sleeper needs.

• You feel the cold, or keep your bedroom cool: choose down, and pay attention to fill power.

• You want something simple and washable on a budget: choose cotton, and expect to replace it sooner.

• You share a bed and sleep at different temperatures: this is where silk often wins, because it adapts rather than simply insulating. (Two single duvets on one bed is also a wonderfully practical Nordic habit.)

A Note From Us

We are two sisters, raised between Eastern and Western ways of living, and we started Elaine & Cocoon with one simple belief: home is a feeling, and much of that feeling is made at night.

Silk is where our story began, because it does something we think matters a great deal: it moves with your body's temperature through the night, so you are not waking at 3am to throw off the covers, only to pull them back an hour later. But if this guide has led you to down or cotton, we are genuinely glad. What we care about most is that you wake up rested.

Our Mulberry Silk Duvet

If silk sounds like you, our Mulberry Silk Duvet is filled with douppioni mulberry silk, reeled from double cocoons for a naturally stronger, more resilient filament that holds its shape over time. It is finished in a fine 100s cotton shell and comes in two weights calibrated for the Swiss indoor climate: 750g for a single and 1500g for a king.

Made by a family owned silk partner we work with directly, from the mulberry leaf to the finished piece. Designed in Zurich, delivered free across Switzerland.

Discover our Mulberry Silk Duvet.

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Frequently Asked Questions

Is silk or down warmer?

Down is warmer for its weight because its clusters trap more still air. Silk is less insulating but far more breathable, which is why many people find it more comfortable through a whole night, especially in heated homes.

Is a silk duvet good for hot sleepers?

Yes. Silk lets excess heat and moisture escape rather than trapping them, which helps keep the climate under your duvet steady. It is one of the best natural choices for people who wake up too warm.

Are down duvets bad for allergies?

Not necessarily. True down allergy is relatively uncommon, and most bedding allergies are caused by dust mites. Well processed down in a tightly woven casing is suitable for many allergy sufferers. Silk contains no feather proteins, which some sensitive sleepers prefer.

Can I use a silk duvet all year round?

In most Swiss homes, yes. Because silk breathes, a single well chosen weight can stay comfortable from winter to summer. Very cold sleepers in cool rooms may still prefer extra warmth in winter.

How long does a silk duvet last?

With gentle care, a good quality silk duvet can last many years. Long filament silk, such as douppioni mulberry silk, holds its structure better than short fibre fills, which can clump or thin over time.

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Wondering what makes a silk duvet worth it? Read What Is a Silk Duvet?, or if you tend to wake up warm,  tune in for our upoming blog post Best Duvet for Hot Sleepers.

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¹ Okamoto-Mizuno, K. & Mizuno, K. (2012), "Effects of thermal environment on sleep and circadian rhythm", Journal of Physiological Anthropology, 31:14.

² Kemp, T.J. et al. (1996), "House dust mite allergen in pillows", BMJ, 313:916.