Pillow marks upon waking: what science really says

In short: pillow marks are not expression lines. They result from mechanical compression of the face against the surface, night after night, always on the same side. The scientific literature is clear about the cause—much less so about the solutions. Here is what we know, what a silk pillowcase can reasonably change, and what it cannot.

This is the question I am asked most often in September, when faces are once again exposed to the harsh light of office spaces: “Why do I still have this mark on my cheek at ten in the morning?” For a long time, I answered like everyone else—“It’s the pillow.” That is true, but it does not tell the whole story. I reread what dermatology really says about it, including what contradicts the claims made by silk brands. Including, sometimes, our own.

Where pillow marks really come from

An expression line deepens because a muscle contracts: we frown, smile, or squint. A pillow mark, on the other hand, has nothing to do with the muscle. It appears when facial skin is compressed and sheared against a surface for several hours, in a position we do not control.

The reference on the subject remains the article by Goesel Anson, Michael Kane, and Val Lambros, “Sleep Wrinkles: Facial Aging and Facial Distortion During Sleep”, published in the Aesthetic Surgery Journal in 2016. The authors describe three forces at work—compression, shear, and tension—which deform the tissues as soon as the face rests on its side or face down on the pillow. They also recall a fact that explains a great deal: on average, about two-thirds of sleepers sleep on their side, just under a third on their backs, and a small minority on their stomachs. In other words, most of us spend the night with half of our face under pressure.

On young, elastic skin, these folds fade within a few minutes. The point raised by the authors lies elsewhere: with repetition, and as the skin loses collagen and elasticity, some folds take increasingly longer to disappear. A cross-sectional study conducted in 2025 among patients over 60 at the Universidade Federal de Pelotas (Brazil) mapped these “sleep lines” in older people; the most common pattern was two lines on each side of the face. The same study compared these marks with sleep quality measured using the Pittsburgh index—a sign that the subject now interests researchers beyond aesthetics.

One honest clarification: these studies describe an association and a mechanism. They do not demonstrate that any given textile prevents the phenomenon.

Expression lines and pillow marks: don't confuse them

The test is simple: if the mark is asymmetrical and follows the side you sleep on, it is a pillow mark. If it is symmetrical and moves when you make a facial expression, it is an expression line.

What silk changes—and what it does not

I prefer to be precise, because this is where many approximations are found.

What it reasonably changes

• Friction. This is silk's best-documented property: its very smooth surface offers significantly less resistance than cotton. The most frequently cited measurements—around 40% less friction—come from laboratory tests commissioned by brands, not independent clinical trials. I mention them for what they are worth: an approximate scale, not proof.
• The number of fabric folds. A silk pillowcase with a sufficient weight stretches over the pillow instead of wrinkling like an accordion. These fabric ridges are what leave the sharpest lines on the cheek.
• Retained moisture. Cotton absorbs more water and oils. With silk, your evening serum or cream migrates less into the fabric, so skin that stays supple recovers better from compression.
• Thermal stability. Less nighttime sweating means fewer awakenings, and therefore fewer hours spent stuck in the same position.

What it does not change

Silk does not eliminate compression. If your cheek presses against a firm pillow for six hours, the fabric will not make the force disappear — at best, it distributes it a little better. Some dermatologists also believe that, to date, there is no solid evidence to claim that a silk pillowcase prevents wrinkles. It’s a defensible position, and I’d rather give it to you than sell you a promise that science does not support.

Silk affects the surface and the way you glide. Your sleeping position, pillow firmness, and skin elasticity affect depth. All three matter, and the pillowcase is only one of them.

My five-point routine

1. Notice which side you sleep on. One week is enough: the mark always appears on the same side. That’s your support side.
2. Pull the pillowcase taut. A pillowcase that’s too large for the pillow creates ripples, and every ripple is a potential line. Choose the right size, not the next size up.
3. Moisturize beforehand, not when you wake up. Supple skin handles compression better than dehydrated skin that retains the imprint.
4. Lower your pillow by one level. A pillow that’s too high presses your cheek against the surface. The mark is as much about height as it is about fabric.
5. Wash the pillowcase every week. When it comes to your face, textile cleanliness matters at least as much as the fabric itself — it’s the same reasoning I explained in our article on silk and acne.

Which pillowcase to choose, specifically

Two criteria make the difference on this specific subject.

GSM first. Lightweight silk wrinkles and shifts; denser silk stays taut and slides better. For a pillowcase, 19 momme is a good balance, while 22 momme is a step up in structure and durability. If the unit is unfamiliar, everything is explained in our momme guide.

The size comes next, too often overlooked: a 65 × 65 pillowcase on a 50 × 70 pillow creases all night long. We explain the size matches in detail in the guide to choosing a silk pillowcase.

Frequently asked questions

Do pillow marks become permanent?
On young skin, they fade within a few minutes. The work of Anson and co-authors suggests that with repetition and the age-related loss of elasticity, some creases fade more slowly. This is a described trend, not an individually measured inevitability.

How long do they take to disappear?
From a few minutes to one or two hours, depending on hydration, age, and how long the pressure lasts. If they persist for more than half a day on a repeated basis, it is worth discussing them with a dermatologist.

Is a silk pillowcase enough to prevent them?
No. It reduces friction and fabric creasing, which often softens the appearance of the mark. It does not eliminate the pressure caused by your sleeping position.

Is sleeping on your back really better?
Mechanically speaking, yes: the face is no longer compressed. In practice, you cannot choose your position while sleeping, and poor-quality sleep costs the skin more than a temporary mark.

Silk or polyester satin?
Both glide. Only mulberry silk combines this smoothness with good moisture and temperature regulation. We compare the two in detail in our article silk or satin.

If you want to start with just one item, start with this one: it’s the only one that touches your face for seven to eight hours a night. Our pillowcases are gathered in the Pillowcase collection, in 19 and 22 momme.

— Mei, for the StudioSoie Journal

Sources: Anson G., Kane M.A.C., Lambros V., “Sleep Wrinkles: Facial Aging and Facial Distortion During Sleep,” Aesthetic Surgery Journal, 2016;36(8):931-940 — PubMed. “Frontal wrinkles in the elderly: prevalence, patterns and association of sleep lines with sleep quality,” cross-sectional study, Universidade Federal de Pelotas, 2025 — PubMed.