Almost every new parent ends up owning both and is never told the difference. It is worth two minutes, because buying the wrong one is how you end up with a drawer full of blankets and still nothing that does the job.
What a muslin actually is
Muslin is a loose, open-weave cotton. That open weave is the whole point: it is breathable, it dries fast, and it gets softer every time you wash it. A new muslin feels slightly crisp; by the tenth wash it is the softest thing in the house.
What it is for, in practice: mopping, burping, covering a pram from the sun, screening while feeding, a clean surface on a strange floor, and — in the larger sizes — swaddling.
What it is not for: warmth. A single muslin adds almost no insulation. That is a feature, not a fault.
What a cellular blanket is
A cellular blanket is the one with the small holes punched through it, usually in cotton or acrylic. The holes are deliberate. They trap air, which is what makes a blanket warm, while still letting air move through if a baby's face ends up near it.
It is the traditional answer to a specific problem: how do you add warmth to a cot or pram without adding a dense, heavy layer.
The practical difference
| Muslin | Cellular blanket |
| Open cotton weave, no insulation to speak of | Holes trap air, adds real warmth |
| Everyday cloth: mop, cover, screen, swaddle | Layering in a cot, pram or car seat |
| You want several — six is not excessive | Two is usually plenty |
| Washes and dries in hours | Slower to dry, washed far less often |
Which sizes matter
For muslins, size decides the use. Around 70–80cm squares are the everyday cloths you keep in every room. Anything approaching 120cm becomes a genuine swaddle and a pram cover, and it is the one worth owning if you only own one.
A word on layers and warmth
Deciding how many layers a baby needs is a question for current NHS and Lullaby Trust safer-sleep guidance, not for a shop. The general principle they set out is that overheating is the risk to manage, and that loose bedding in a cot is not recommended for babies under twelve months. If you are unsure, your midwife or health visitor is the right person to ask.
What we can say is the practical bit: a muslin is a cloth, a cellular blanket is a layer, and treating one as the other is where people go wrong.
So which should you buy?
Both, but not in the same quantity. Several muslins, because they are in constant use and constantly in the wash. One or two cellular blankets, because they are a layer and layers do not need replacing daily.
If you are starting from nothing, start with muslins — they are the ones you will reach for twenty times a day.
If you are buying
Our 80 x 80cm cotton muslin squares are the everyday workhorses — four to a pack from £6.99, up to 24 in a pack, dispatched from the UK in 1–3 working days.
We do not stock a cellular blanket at the moment. What we do have is a faux fur blanket for pram and floor use — which is a layer, not a cot blanket, and we would not put it in a cot under twelve months. Still working out how many muslins you need? That one has a number in it.