The complete guide
How to Choose a 65 x 65 cm Silk Pillowcase
The problem with square pillows
Square pillows look wonderful on a made bed. They also make shopping for covers unexpectedly annoying.
Walk into most bedding aisles and you will find rows of 50 x 75 cm pillowcases, a handful of 50 x 70 cm, and if you are lucky, one lonely square option in a print you do not want. Silk makes this worse. Silk bedding tends to be produced in the sizes that sell in the biggest volumes, so the 65 x 65 cm continental square often gets skipped entirely.
That leaves people with a nice square pillow doing one of two things. Either they jam it into a rectangular cover, where it bulges in the middle and leaves a floppy tail, or they keep a cotton cover on the square and a silk one on the pillow they actually sleep on. Neither is a great answer if you bought the square pillow to sleep on in the first place.
This pillowcase is cut to 65 x 65 cm, roughly 26 x 26 inches, for exactly that gap.
What 19 momme actually tells you
Momme is the number most people skim past, and it is genuinely the most useful spec on a silk pillowcase.
It measures weight for a set area of fabric. Higher momme means more silk packed into the same square of cloth. In bedding, the usual range runs from about 16 at the light end up to 25 at the heavy end. This one is 19, which sits comfortably in the middle.
What does middle feel like? Light enough to stay cool and drape softly over a plump pillow. Dense enough that the fabric has presence in the hand rather than feeling thin or papery. A 16 momme piece will feel airier and more delicate. A 25 momme piece will feel noticeably more substantial and will usually cost more. For most people, 19 is the sensible landing spot, which is why the best 19 momme silk pillowcase options tend to be the ones that sell steadily year after year.
One more thing worth knowing. Momme describes weight, not quality on its own. A 19 momme fabric made from long mulberry fibres is a different thing from a 19 momme fabric made from short, mixed fibres. Here the fabric is stated as 100% mulberry silk, which is the long-fibre variety.
Silk on both sides matters more than it sounds
A lot of silk pillowcases are silk on one face and something cheaper on the other. Cotton, polyester, a blend. It keeps the price down and in fairness, you only sleep on one side.
Except you do not, really. You flip the pillow when one side gets warm. You turn it over when you change position. You hand it to a guest and they put it the other way round without thinking. And over time, the two faces behave differently in the wash, so one side ages faster than the other.
Both faces here are mulberry silk. Flip it as often as you like and nothing changes. If you are comparing the best double sided silk pillowcase against a cheaper single-sided one, that is the practical difference, not just a spec-sheet bragging point.
Why the envelope closure is the right call
Pillowcases close in three common ways. A zip, a set of ties or buttons, or an envelope flap.
Zips are tidy but they put a strip of metal or plastic near your head. On a square pillow that gets turned a lot, you notice it. Zips also catch on other laundry in the machine and can pull threads in a fine fabric.
Buttons and ties look lovely and take ages to do up when you are tired.
The envelope closure is a flap of fabric sewn inside the open end. You push the pillow in, fold the flap over and that is it. Nothing hard, nothing fiddly, nothing to break. On a 65 x 65 cm square the flap has plenty of fabric to work with, so the pillow stays tucked in overnight. If you have been hunting for the best silk pillowcase without a zip, this is the format you want.
Getting the fit right
Please measure your pillow. I know that sounds like obvious advice, but square pillows in Europe are not standardised the way rectangular ones are, and sizes drift between manufacturers.
Lay the pillow flat on the bed and run a tape measure edge to edge across the middle, then again in the other direction. If you get something close to 65 x 65 cm, you are in the right territory. If you get 80 x 80 cm, which is also a common square, this cover will be far too small.
Also think about how full the pillow is. A soft, under-filled pillow will leave the corners of the cover looking empty and creased. A firm, well-filled one gives you clean edges and that neat shape you were after when you bought a square in the first place. The best 65 x 65 silk pillowcase in the world still looks sloppy over a tired pillow.
White, and why plain is useful
There is a reason hotels stick to white.
A solid white silk pillowcase does not compete with anything. It layers against patterned duvet covers, it sits fine with linen, it reads clean in a dark room and bright in a pale one. If you redecorate, it still works. If you are building the best plain white bedding setup, square silk at the back is one of the easier wins.
It also makes stains obvious, which some people hate and some people prefer. Personally I would rather see a mark and deal with it than wonder what is lurking on a dark cover.
Looking after it
Silk has a reputation for being high maintenance. It is not as bad as people think, but it does have rules.
Wash cool. Hand wash in a basin if you have the patience, or use a silk or delicates cycle with the pillowcase inside a mesh laundry bag. The bag is doing real work, keeping the fabric away from zips and hooks in the drum.
Use a mild detergent made for delicates. Standard detergents often contain enzymes that break down protein fibres, and silk is a protein fibre. Skip fabric softener too, it does nothing useful here and can leave a dull film.
No bleach, even on white. Bleach weakens silk and can turn it yellow over time, which is the opposite of what you wanted.
Do not tumble dry. Roll the pillowcase in a clean towel, press gently to take out the water, then dry flat or hang it away from direct sunlight and away from radiators. Heat and strong sun are what dull silk fastest.
If it needs pressing, use the lowest iron setting, work on the reverse and go while the fabric is slightly damp.
Do all that and a silk pillowcase lasts a long time. Ignore all of it and you will be disappointed in a season.
Who this suits
It suits anyone who already sleeps on a 65 x 65 cm continental pillow and has given up finding silk in that size. It suits people building a layered bed who want two squares at the back in a smooth white finish. It suits anyone who finds cotton feels rough or warm against the face and wants something lighter, and anyone who simply likes how silk looks on a made bed.
It does not suit rectangular pillows, 80 x 80 cm squares, or anyone who wants a complete set, since this is one pillowcase.
The short version
This is a single white pillowcase in 100% mulberry silk, 19 momme, silk on both faces, cut to 65 x 65 cm with an envelope closure instead of a zip.
Measure your pillow first. If it comes in around 65 centimetres each way, this will fit it properly, and you can stop looking for a continental silk pillowcase that actually exists in your size. Wash it cool, dry it flat, keep it out of the sun, and it will keep that smooth white surface for years.