Champagne silk satin and pearl polyester satin swatches, one folded to reveal its matte reverse.

Silk or satin: the real difference

The short answer

Silk is a fibre; satin is a weave. A satin pillowcase can be made of silk, polyester or another fibre, so the word “satin” tells you about the shine, not the material. The sewn label tells you the rest: look for “100% silk”, then for the weight in momme, the grade and a certificate number you can check yourself.

Two pillowcases hang side by side in a shop. Both are smooth, both catch the light, and both are called satin. One costs a fraction of the other.

On forums, the same worry comes back every week: is my “silk” pillowcase really silk, and how would I know? The answer starts with two words that are often used as if they meant the same thing. They do not, and once you see why, a label becomes easy to read.

What is the difference between silk and satin?

Silk is what the fabric is made of. Encyclopaedia Britannica describes the silk of commerce as the filament spun by the domesticated silkworm, Bombyx mori, which is fed on mulberry leaves. Each cocoon is a single continuous thread, with a usable length of about 600 to 900 metres, made of a protein called fibroin. Mulberry silk is that fibre.

Satin is how the fabric is woven. Britannica defines it as any fabric made with the satin weave, one of the three basic textile weaves, with a smooth, lustrous face and a duller back. Satin was first a silk fabric; today it is woven from other fibres too, and an all-cotton cloth in the same structure is called sateen.

So one word answers “what” and the other answers “how”:

  • Silk satin: silk fibre in a satin weave. Our pillowcase is this.
  • Polyester satin: a synthetic fibre in the same weave.
  • Cotton sateen: cotton in a satin structure, softer in its shine.
  • Silk twill or silk crêpe: silk again, in other weaves, with less gleam.

Why does satin shine?

The shine is in the weave. In a satin weave, each thread passes over several others before it dips under one, so the face of the cloth is made of long, smooth floats that reflect the light. The back, where the threads cross more often, stays matte. Silk, polyester, viscose and nylon can all be woven this way, and all of them will gleam.

That is why a photograph cannot settle the question. Two satins can look the same on a screen and feel quite different in the hand, on the pillow and in the wash. The shine tells you a satin weave was used. Only the fibre tells you what you are sleeping on.

How can you tell if a pillowcase is real silk?

Start with the label, not the sheen. In the European Union, a textile product sold to consumers must carry a label, often sewn in, that gives its fibre composition in decreasing order of percentage, using fibre names from an official list. It may say “100%” or “pure” only when it is made of one fibre alone. Words such as “silky”, “silk feel” or “satin touch” describe an impression; they are not fibre names.

Then read the details, in this order:

  1. The fibre. “100% silk” or “100% mulberry silk”. A blend has to list each fibre with its percentage.
  2. The weight. Silk is weighed in momme. One momme is about 4.34 g of silk per square metre, so 22 momme is about 95 g. Our guide to what 22 momme means sets out the numbers.
  3. The grade. Mulberry silk is sold by grade, and a precise listing names it. Ours is Grade 6A, long fibre, and the sewn label says so.
  4. The certificate. An OEKO-TEX® label carries a number. Type it into OEKO-TEX’s Label Check and the certificate appears, or it does not. Our pillowcase carries OEKO-TEX® STANDARD 100, certificate 26.HCN.36686, tested for harmful substances. Read what the OEKO-TEX label tells you, and what it does not.
  5. The price. A very low price beside “100% mulberry silk” is a reason to read the label twice.

Forums often suggest burning a thread, since silk and polyester behave differently in a flame. It can only be done once you own the piece, it means holding a flame to something you paid for, and a clear label plus a certificate you can check answer the question before you buy.

Is silk or satin better for hair?

Compared with an ordinary cotton weave, both give hair a smoother surface to move across. The American Academy of Dermatology (AAD) says so plainly in its advice for curly hair: satin or silk bonnets or pillowcases “may also reduce friction and preserve your hairstyle”. A well-made polyester satin is a fair, inexpensive way to try a smoother surface.

The difference is the fibre. Silk is a protein filament, reeled as one long thread rather than spun from short fibres. Britannica adds that it can hold as much as a third of its weight in water without feeling damp. What we say about our own silk fits in one line: hair glides over silk instead of rubbing, so blowouts last and mornings start with fewer tangles.

At night, the difference is also one of touch. At 22 momme, silk feels fluid and substantial, with a soft sheen rather than a mirror shine. For warm sleepers, our wording stays short: temperature-regulating silk, comfortable in every season.

Silk or satin: which should you choose?

Choose polyester satin if you want a smooth surface at the lowest price and the simplest care. It is a reasonable choice, and nothing to apologise for.

Choose silk if you want the fibre itself: a protein filament, a weight you can read in momme, a grade, a certificate you can check, and the particular hand of silk. Whichever you pick, compare like with like: fibre with fibre, weave with weave, and a label with a label.

Our silk pillowcase, line by line

What to check The Siluxe silk pillowcase
Fibre 100% mulberry silk
Weave Satin
Weight 22 momme, about 95 g of silk per square metre
Grade 6A, long fibre
Certificate OEKO-TEX® STANDARD 100, certificate 26.HCN.36686, tested for harmful substances
Closure Envelope closure, with no zip or button
Detail Embroidered S monogram, tone on tone
Sizes Standard 50 × 70 cm (Rose gold, Gold) or Euro 65 × 65 cm (Gold)
Care Hand wash, or machine wash at 30 °C on a delicate cycle, inside out in a mesh bag
Design Designed in Paris

Where Siluxe fits

The Siluxe silk pillowcase is silk satin in the plainest sense of the words: mulberry silk fibre, satin weave, every detail on the label. It comes in Standard 50 × 70 cm, in Rose gold or Gold, or in Euro 65 × 65 cm, in Gold, with an envelope closure and an embroidered S monogram, at $99. See the pillowcase.

Complimentary delivery from $100 on USD orders: the pillowcase with a scrunchie M qualifies.

FAQ

Is satin always polyester?

No. Satin is a weave, not a fibre, and it can be woven from silk, polyester, viscose or nylon. Many satin pillowcases are polyester, which is why the two words get mixed up. The label settles it: it has to name the fibre.

Is silk satin real silk?

Yes. Silk satin is silk fibre woven in a satin structure, which gives it its smooth, bright face and its matte back. Look for “100% silk” or “100% mulberry silk” on the sewn label, with the weight in momme.

What is the difference between satin and sateen?

Both use a satin structure. Satin is often a filament fibre, such as silk or polyester, with a bright face; sateen is cotton, spun from short fibres, with a softer shine. Britannica calls an all-cotton fabric in the satin structure sateen.

How can I check an OEKO-TEX certificate?

Find the number on the label or the product page, then enter it in OEKO-TEX’s Label Check. A valid certificate shows its holder and the articles it covers. Our pillowcase carries OEKO-TEX® STANDARD 100, certificate 26.HCN.36686, tested for harmful substances.

Is 22 momme good for a silk pillowcase?

It is a substantial weight: about 95 g of silk per square metre, against about 82 g at 19 momme. Read it with the fibre, the weave, the grade and the sewing, since momme measures weight, not quality on its own.

Sources

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