Which Pillowcase Size to Choose (Silk Doesn't Forgive Approximation)

In short: measure your pillow lying flat, choose a pillowcase of identical dimensions, and don't let a gap of two or three centimetres slip through. With cotton, it can be forgiven. With silk, you can see it and feel it.

It's the last question we ask ourselves before buying, and the one that disappoints the most people: which pillowcase size should I choose? Not because silk is temperamental, but because a pillowcase that doesn't fit properly spoils exactly what you came for — a smooth, crease-free surface against your cheek. We are entering the weeks when orders pick up, for oneself as much as for gifts. Best to settle the question of centimetres now, at leisure.

Measure, don't guess

Two minutes is enough, and it saves you a return.

• Lay the pillow flat on the bed, without pressing it down or plumping it up.
• Measure from seam to seam: width first, then length.
• Note them in this order — 50 × 70, never 70 × 50. This is the convention on all our product pages, and it will stop you ordering one size for another.
• If the pillow is domed, still measure it flat. A pillowcase is chosen by the dimensions of the pillow's ticking, not by its volume.

And if the original label is still legible, it gives you the answer without a tape measure.

French sizes, and yours

A distinctly French quirk: the square remains the dominant format in France, whereas the rectangular has become the norm almost everywhere else in Europe. This is why a bedding set brought back from a trip, or ordered from a foreign website, doesn't always fit properly.

Format	Dimensions	Where you'll find it
Square	60 × 60 cm	The traditional square, still very common in French bedrooms
Large square	65 × 65 cm	The most common in France today
Rectangular	50 × 70 cm	The European standard, common on newer beds
Long rectangular	50 × 75 cm	Hotel size, adopted by many bedding brands
Small	40 × 60 cm	Child's bedroom, spare pillow, travel
Bolster	50 × 90 to 50 × 180 cm	Beds 90, 140, 160 or 180 cm wide

At Studio, our silk pillowcases come in sizes from 40 × 40 to 80 × 80, bolsters included. In other words: there is almost always a size for you, as long as you know what it is.

Why silk is unforgiving of approximations

Three very practical reasons, and none of them is about luxury.

1. It doesn't stretch

Silk satin is a woven fabric, not a knitted one, and contains no elastane. A cotton jersey forgives a three-centimetre gap by stretching a little; silk doesn't. A pillowcase that is too snug puts the seams under tension with every movement of your head, and the corners are the first to wear.

2. Too large, it creases

The excess fabric doesn't disappear: it forms waves that settle exactly where your cheek rests. Yet creasing is precisely what you hope to avoid by switching to silk — it's what imprints the skin on waking, as I explained when writing about pillow marks.

3. It slips

It's one of its qualities, and also one of its constraints. A pillowcase that is too loose turns around the pillow during the night and ends up crooked by morning. Well fitted, it stays in place without you thinking about it.

The rule, then: the same dimensions as the pillow. Torn between two sizes? Choose the smaller if your pillow is flat or slightly compressed through use, and the larger only if it is truly domed.

The case of the very full pillow

A new, well-plumped pillow “eats up” one to two centimetres. On a 65 × 65 pillow stretched taut like a ball, a 65 × 65 pillowcase will be snug but fine: the silk settles into place after a night or two. Beyond that — a thick memory-foam pillow, an ergonomic contoured model — it is better to go up a size than to force it.

The closure matters as much as the size

Two pillowcases of the same dimensions won't hold in the same way, depending on their finish.

• The inner flap (known as the “envelope” closure) folds the fabric inside the pillowcase. Nothing hard against your cheek, no visible closure — but it requires a pillowcase that is genuinely the right size, otherwise the pillow slips out.
• The side zip holds more firmly, which helps with thick pillows or restless sleepers. Simply check that it sits neatly on the side and feels discreet to the touch.

It's the same reasoning as for the fitted sheet and pocket depth: the dimensions determine compatibility, the finish determines how it holds.

And what about momme?

The weight doesn't replace the right size, but it changes the way the pillowcase fits the pillow. A 19 momme drapes softly and follows the shape. A 22 or 25 momme has more body and creases less readily. A 30 momme is decidedly dense: it holds the corner better on a well-filled pillow, and is a little more forgiving of a slightly generous size. If the unit means nothing to you, momme is the unit that changes everything when buying silk.

Giving a pillowcase without knowing the size

It's the situation of the season, and it can be handled very well.

• Look at a photo of the bed. A square is spotted immediately, even in a holiday snapshot.
• Make a reasonable bet. In France, 65 × 65 if the person sleeps on a square, 50 × 70 otherwise. These are the two most widespread sizes.
• Ask the question indirectly. “Do you sleep on a square or a rectangular pillow?” goes down better than a request for measurements, and is enough to settle it.
• Choose something without a size. Sleep mask, scrunchie, scarf: silk accessories carry no risk of getting the size wrong and make an equally fitting gift.

Five mistakes that come up often

1. Measuring the worn pillowcase rather than the pillow. An old pillowcase may have stretched or shrunk; it isn't a reliable reference.
2. Swapping the numbers. 50 × 75 and 75 × 50 don't describe the same piece on a product page.
3. Choosing “a bit bigger to be safe”. With silk, the extra margin becomes creases, not comfort.
4. Forgetting the bolster. You renew your bedding, you choose the pillowcases, and it stays there, in cotton, beneath everything else.
5. Ordering two different sizes for a double bed. It happens when each person has their own pillow: check both, as they aren't always identical.

Frequently asked questions

What is the most common pillowcase size in France?
The 65 × 65 cm square, followed by the 50 × 70 cm rectangular. The 60 × 60 is still found on older bedding.

Can a silk pillowcase be slightly larger than the pillow?
One to two centimetres go unnoticed. Beyond that, the excess fabric forms creases under your cheek and the pillowcase tends to twist during the night.

What if my pillowcase is a little too small?
Avoid forcing it: the seams work under tension with every movement and wear faster at the corners. It's better to keep that pillowcase for a flatter pillow.

Does silk shrink in the wash?
Washed cold, by hand or on a delicate cycle in a mesh bag, and dried flat away from sunlight, a mulberry silk pillowcase keeps its dimensions. Heat and a fast spin are what cause problems.

Do I need the same size for a 19 momme pillowcase and a 30 momme pillowcase?
Yes. Momme describes the density of the fabric, not the dimensions: you always choose the pillowcase to match the size of the pillow.

Take the tape measure tonight, jot down two numbers on a scrap of paper, and the rest becomes simple. Discover silk pillowcases, from 40 × 40 to 80 × 80.

— Inès, for the StudioSoie Journal