A silk pyjama set should fit at the shoulder and the hip. The waist is the least important measurement on the page, and sizing up to fix riding-up shorts usually makes it worse — shorts climb because the hip-to-hem length is too short for your seat, not because the waistband is tight. Check garment length against your own hip depth before you check the size chart.
This is the return we see most, and it is almost always a length problem wearing a size problem's clothes.
The Three Measurements That Decide It
Shoulder to bust point. On a camisole or a collared top, the strap or shoulder seam sets where everything else lands. If the shoulder sits right, a slightly loose body reads as intentional. If the shoulder is wrong, no amount of body ease rescues it. Adjustable straps fix this; a fixed shoulder seam does not.
Hip circumference, at the fullest point. Not the waist. Silk shorts and trousers pass over the hip on the way to their final position, and the hip decides whether they get there.
Garment length, in centimetres. The number that solves riding-up, and the one most brands omit. You want the hem to sit below the crease where thigh meets seat. If it lands on that crease, movement will push it up every time you sit down.
Why Silk Shorts Ride Up
Three things combine, and only one of them is size.
First, silk has very low friction against skin. Cotton grips slightly and stays put; silk slides, which is exactly why it feels the way it does at 2 a.m. Anything that pushes the hem upward meets almost no resistance.
Second, the seat is the widest part of the garment's path. As you sit, stand or roll over, fabric is pulled inward and upward across the fullest curve. Short shorts have less length below that curve to spare, so the hem migrates.
Third — and this is the one people get backwards — an elastic waistband cannot hold a hem down. It anchors the top of the garment, not the bottom. Sizing up gives you more waist room and no more length, so the shorts still climb, and now they also slip at the waist.
The fix is a longer inseam or a deeper rise, not a bigger size. If a brand publishes only "S / M / L" and no length, that is your signal to ask.
The Fix, By Symptom
| What is happening | Actual cause | What to change |
|---|---|---|
| Shorts ride up when you sit | Hem sits at or above the thigh crease | Longer garment length or deeper rise — not a bigger size |
| Waistband rolls down | Elastic too narrow for the hip-to-waist difference | Wider elastic, or a tie waist you can set yourself |
| Fits the chart, pulls across the seat | Charts use waist; your ratio is hip-led | Size to the hip, accept waist ease |
| Straps slip off the shoulder | Strap length, not body size | Adjustable straps, or shorten by two centimetres |
| Trousers pool at the ankle | Inseam length | Cropped cut, or hem them — silk hems beautifully |
Read the Numbers, Not the Letter
We publish garment lengths because a letter tells you nothing across brands. The Short Notice Silk Set is nineteen-momme silk with the camisole at 45–48 cm and the shorts at 30–32 cm, so nothing is longer than it needs to be. It has an elastic waist and no drawstring, which is exactly why we say to size it from the hip — there is no cord to compensate with afterwards.
Here is how to use a number like that. Measure from your natural waist down over the fullest part of your seat to where you want the hem to land. If that measurement is longer than the garment length, the shorts will ride. It takes thirty seconds and it is more reliable than any size chart, because it compares the garment to your body rather than to an average.
Sets With Sleeves Play by Different Rules
Once you are in a collared, long-sleeved set, the fit problem moves upward. The shoulder seam and the sleeve head decide comfort; the trouser is usually forgiving because full length has plenty of fabric below the seat.
The Long Weekend Silk Set is nineteen-momme mulberry silk with a notched collar and a tie at the waist — and the tie is the point. A tie lets you set the waist yourself, which means you can size for the hip and shoulder and still have the waist sit where you want. If you are between sizes on a full pyjama set, the version with a tie is the safer buy.
Cropped sets sit between the two. The Feather Weight Silk Set has cropped sleeves and cropped trousers, so the ankle and wrist points are fixed by design rather than by your height — worth checking against your own proportions rather than assuming a crop lands where the photo shows it.
Two Small Alterations Worth Doing
Silk takes alteration well, and both of the common ones are cheap. Shortening a strap by two centimetres solves most slipping-strap complaints and takes a tailor minutes. Re-hemming a trouser is equally straightforward, and silk holds a narrow rolled hem cleanly — the same finish used on a slip edge.
What is not worth altering is the seat or the rise. That is a rebuild, not an alteration, and the cost usually approaches the garment.
FAQ
Why do my silk pyjama shorts ride up?
Because the hem sits at or above the crease where thigh meets seat, and silk has almost no friction against skin to hold it there. It is a length problem, not a size problem — sizing up adds waist room without adding length, so the shorts still climb and the waistband now slips too.
Should I size up in silk pyjamas?
Only if the hip measurement requires it. Size to the hip rather than the waist, since the hip is the widest point the garment has to pass over. If you are between sizes, choose the set with a tie waist rather than fixed elastic, because a tie lets you set the waist independently.
How should a silk pyjama top fit?
The shoulder seam or strap position should be right first — that sets where everything else lands. A little ease through the body is correct for sleepwear and reads as intentional in silk. Straps that slip are a strap-length issue, usually solved by shortening about two centimetres.
What length should silk pyjama shorts be?
Long enough that the hem sits below the crease where thigh meets seat when you sit down. Measure from your natural waist over the fullest part of your seat to that point, then compare it with the garment length on the listing. Ours run 30–32 cm for exactly this comparison.
Can silk pyjamas be altered?
Yes, for straps and hems, both of which are quick and inexpensive, and silk takes a narrow rolled hem cleanly. Altering the rise or the seat is a rebuild rather than an alteration and usually costs close to the garment itself.
For slips specifically, see how a silk slip should fit, or how lingerie sizing works. Browse the silk collection.
