A zip swaddle does the job a folded cotton cloth used to do, without the folding. There is no technique to learn and nothing to get wrong at three in the morning, which is the point. Here is what one is, how to put your baby in ours, and the two checks worth doing before you close the zip.
What a zip swaddle is
It is a one-piece sleep garment shaped like a bag, with a zip running down the front and closed pockets at the shoulders for the arms. Your baby goes in, each arm slides into a pocket, the zip closes from the neck to the hem. Nothing is wrapped, nothing is tucked, and nothing comes loose in the night the way a folded blanket can.
The arms staying in is the part that separates a swaddle from an ordinary sleep bag. Very young babies startle in their sleep and throw their arms out; a swaddle keeps them contained. An ordinary sleep bag leaves the arms free and is meant for later.
Why parents use one
Mostly for the moment they put the baby down. Your baby is settled against you, and the second they meet the mattress they are awake and cross about it. A snug garment keeps that wrapped-up feeling around them once your hands are gone.
The second reason is plainer: at three in the morning you want one movement, not seven. A zip is one movement.
How to use ours
- Warm it on your chest. Five minutes before the last feed, hold the empty sack against your chest. It goes into the crib carrying your warmth and your scent instead of the cold of a drawer.
- Arms in, one zip. Lay your baby in, tuck each arm into a wing pocket so the hands stay covered, and zip from the neck to the hem.
- Down on their back. Into the crib on their back, on a bare firm surface, with nothing loose around them.
Two checks before you close the zip
Temperature. Dress your baby for the room the way you normally would, underneath the sack — a short-sleeved bodysuit in a warm room, a long-sleeved one as it cools. Check the back of the neck rather than the hands: warm and dry is right, clammy means take a layer off.
Fit. The neck opening should sit close enough that your baby cannot work down inside the sack, and the body should be roomy enough for the hips and legs to move freely. Nothing should reach the face. Check the fit before the first use, not on the first night you are exhausted.
Choosing a size
Ours come in three sizes — 0–3 months, 3–6 months and 6–9 months — and they run by age, not by weight. The months are a guide, not a rule; babies of the same age differ by a lot. The signal to move up is the shoulders reaching the shoulder seam, and the signal to stop using an arms-in sack altogether is the first sign your baby is trying to roll.
Common questions
Can my baby's arms come out? Not by design — the pockets are closed at the tip, so the hands stay covered rather than working free.
What goes underneath? A bodysuit, chosen for the room. Nothing else goes in the crib.
How do I wash it? With the rest of the baby wash, and it is worth owning more than one, because the one you need is always the one in the machine.
When do we stop? At the first signs of rolling. That is a hard stop, not a soft one.
You can see the six prints and all three sizes on the newborn page, and the fit details on the size guide.