Onesies for sleepovers and pyjama parties

A sleepover is a small production, and the costume is a surprisingly large part of it. Children turn up in whatever pyjamas they own, someone is cold at midnight, someone else is embarrassed by their pyjamas, and the evening takes twenty minutes to settle. A onesie fixes most of that at once, which is why they have become standard kit for pyjama parties in the UK.

Here is how to make it work rather than just adding another thing to buy.

Why a onesie earns its place at a sleepover

It solves the cold floor

Children sleep on air beds, in sleeping bags, on floors, half out of the covers, in a house where the heating has gone off at eleven. A fleece one-piece covers legs and feet and means nobody is up at two in the morning being cold and miserable.

It makes it an occasion

The change of clothes is the moment the evening starts. Putting on a costume is more of an event than putting on pyjamas, and it does a lot of the work of making a normal Friday feel special.

It levels the room

This is the quiet one, and it matters more than people expect. Children are sensitive about their pyjamas in front of friends. If everyone is a dinosaur, nobody's pyjamas are being judged, and the child who was dreading getting changed relaxes.

Buying for children

Measure them, do not go by age

Children's onesies are sized by height, not by age, and children of the same age vary hugely. Stand them against a wall with their shoes off and measure properly. It takes a minute and it prevents the most common problem. The full method is in our size guide.

Size up, always

A slightly big onesie is comfortable and lasts an extra winter. A slightly small one pulls at the shoulders every time they move and gets abandoned. Turn the cuffs back and let them grow into it.

Open ankles are usually the better buy

Closed feet are warmer but they are also slippery on wooden stairs, they wear through at the sole, and they need the height to be exactly right. For a house full of children running about, open ankles with their own slippers is the more practical choice.

Check the zip pull

Younger children will be doing this themselves, in a hurry, in the dark, on a bathroom trip. A long, easy zip pull is worth more than any design feature.

Running the evening

Tell the parents in advance

If the plan is onesies, say so on the invitation. Half the guests will already own one, and the other half will either buy one or arrive knowing what to expect. Springing it on people is how you end up with one child in normal pyjamas feeling left out, which is the exact opposite of the point.

Keep a spare

If you host regularly, one spare onesie in a middling size is worth having in the cupboard. It covers the child who forgot, the child whose bag went home in the wrong car, and the inevitable drink incident. This is the single most useful thing in this article if you have a child who hosts.

Matching or not?

Both work, for different parties.

• Matching set: better for a birthday, where the onesie is part of the party bag and the point is the photograph. Everyone the same animal, different sizes.
• Everyone brings their own: better for a regular sleepover between friends, where half the fun is seeing what everyone turns up as.

The photograph

Take it early, before anyone has spilled anything and while everyone still has their hood up. Nobody wants the photograph taken at eleven when two of them are asleep and one has had enough.

Adult pyjama parties

The same logic applies with two adjustments. Adults get hotter, so a design with open ankles and a full zip is much more comfortable over a long evening indoors. And adults are considerably more likely to be sitting still for hours, in which case a hoodie blanket or a lazy robe is a legitimate alternative. Our comparison of the three covers which suits which kind of evening.

Hen weekends deserve a specific mention: a group in matching kigurumis is a cheaper, warmer and considerably more wearable alternative to fancy dress, and unlike fancy dress everyone keeps theirs and uses it. The same trick works at festivals, for the same reason, as we covered in the festival guide.

The morning after

Something will have been spilled on at least one onesie. Deal with it cold and quickly, blot rather than rub, and do not reach for anything containing bleach because it will leave a pale patch on a printed design. Then wash at 30°C, zipped up and inside out, with no fabric conditioner. The reasoning behind each of those is in how to wash a onesie.

Getting it wrong is cheap

If a size misses, 30-day free returns mean a swap costs you an envelope. Keep the packaging until it has been tried on, and if you have bought a matching set, try one on before the rest go under a bed for a fortnight.

Ready to organise one? Browse the collection and find something a room full of children will recognise instantly.