Silk, Satin and Polyester: What Are the Differences?

Silk vs satin vs polyester: a quick comparison

Our pick: for healthier hair and skin, 100% mulberry silk wins on every count. Shop silk pillowcases →

What is silk and the process of making it?

Silk is a natural fiber used by insects as a material for nests and cocoons. Silk fibers reeled from the cocoon of the Bombyx mori are comprised of silk fibroin, which makes up 70-75% of the weight, and silk sericin, which makes up 20% to 25% of the weight. Silk's incredible structure is glued together by sericin, which holds the shape of the cocoon. Lightweight and enticing, silk feels wonderful when worn, thanks to its many great properties.

Does polyester really resemble silk?

"No" is the unquestionable answer to that question. Polyester resembles silk about as closely as a bicycle resembles a car. It's made of synthetic fibers spun from petroleum products in a way that's designed to look like silk — but it isn't silk.

Polyester is a synthetic fiber created from coal and petroleum. It's durable, but it isn't breathable and doesn't absorb moisture well, so it isn't a great choice for the hot summer months.

Is satin really silk?
Not at all. Satin is a weave, not a fiber, and most fabrics identified as "satin" have a soft, shiny finish that can be found on anything from evening bags to upholstery.

What is a satin weave?
A satin weave is characterized by four or more weft threads crossing over one warp thread, or the opposite — four or more warp threads crossing over a weft thread. Weaving involves holding the warp thread or threads stationary on the loom and weaving the weft thread or threads over and under them.

Where does satin come from?
The history of satin goes back to medieval China, when silk was the only material used to produce it. In medieval Arabic, the fabric was known as "Zaitun," which is where the word "satin" comes from. The weave originated in the Chinese port city of Quanzhou, and trade along the Silk Road carried the fabric and weaving techniques across the Middle East. Satin became popular throughout Europe in the fourteenth century, after Italy introduced it in the twelfth century.

Satin vs. silk: what's the difference?
Silk is the fiber, and satin is the weave. Silk fibers can be woven into satin, but silk can also be woven in patterns that wouldn't be considered satin at all. Satin, in turn, can be made from any long filament fiber — not just silk, which is why "satin" sold today is almost always polyester.

For how silk and satin compare for sleep specifically, see silk vs satin pillowcases.

Silk has many advantages. What are they?
Silk is a natural fiber valued for several real reasons:

1. Environmentally friendly. Natural fibers like silk generally have a smaller environmental footprint than synthetic fibers, since they use fewer chemicals during production.
2. Breathability. Silk is a lightweight, breathable fabric, so you're less likely to overheat wearing it through the day.
3. Elasticity. Cared for well, silk garments hold their shape; the fiber's natural elasticity lets it spring back into shape after stretching, to a point.
4. Absorbency. Silk is fairly absorbent, though water weakens the fiber, which is why it needs a gentle hand when washing.
5. Temperature regulation. Silk's ability to regulate body temperature helps you feel cool in hot weather and warm in cold weather — good both for thinness and for insulation.
6. Shine. Under a microscope, silk fibers are smooth and straight, unlike wool, which has a scaly surface. That's why silk feels smoother to the touch and looks shinier to the eye, giving it its luxurious quality.

Is silk better than polyester?
Nothing quite matches the feel of silk against your skin, whether it's silk sheets or a favorite silk scarf.

Cost is where the two fabrics differ most. Real silk costs roughly five times as much as polyester, by a conservative estimate.

Polyester's main drawback is its poor drape, and it tends to cling to skin because it builds up static electricity.

Silk, by contrast, has a luxurious, soft, smooth and natural feel that's wonderful next to skin. Polyester can feel rough, less soft and artificial, and may irritate sensitive skin.

The other difference is durability under stress: polyester typically doesn't wrinkle, crease, shrink or fade, where silk will do all of those things if you're not careful with it. Polyester can also go straight into the washing machine without much thought.

How can you tell the difference between silk and polyester?
If price alone doesn't settle it, a few simple checks will. Starting with price: if a "silk" item is priced too good to be true, it's probably polyester.

Polyester is usually woven evenly, symmetrically and without imperfections. Silk is less perfectly woven and sometimes shows small flaws, with threads that may be slightly twisted.

Hold the fabric up to the light: silk has a subtle sheen that shifts color as the angle changes, while polyester shines the same flat way no matter the angle.

For a full step-by-step, here's how to tell if silk is real.

Polyester pillowcase vs silk pillowcase

The first thing you'll notice in this comparison is the price difference between real silk and polyester satin — silk simply costs more than man-made fabrics. There's also a difference in feel: where silk is soft and smooth, polyester is slippery and a touch rougher.

Both fabrics reduce friction compared to cotton, so both mean fewer split ends than a rough pillowcase — but the real difference shows up in the broader health benefits. Silk's thermal regulation, hypoallergenic qualities, and natural resistance to mold, mildew and dust mites are genuine advantages polyester satin simply can't match. Comparing the two is a little like comparing a well-made original to a passable imitation: the imitation does a version of the job, just without the same comfort or performance.

See also how silk stacks up against the pillowcase most people already own: silk vs cotton.

Polyester pajamas vs silk pajamas
This comparison runs much the same way as the pillowcase one. Both fabrics — especially polyester satin — are smooth, with silk being the smoother of the two. Both are lightweight and can look wonderful cut into well-made pajamas.

The major difference is origin: polyester satin is man-made, while silk comes from an entirely natural fiber. Satin fabric also tends to be thicker and heavier than silk, so it breathes considerably less.

At laundry time, silk pajamas should be hand-washed or dry-cleaned, while satin can usually go straight into the washing machine. Polyester satin typically shines on one side only, like ordinary polyester fabric, while silk pajamas have a soft sheen on both sides. And silk drapes and flows more beautifully than polyester satin ever quite manages.

In the end, the difference between the two fabrics is a little like the difference between daylight and moonlight. Both can shine, but silk shines brighter — and if you can choose freely, silk is simply the better fabric of the two.