PUL vs Wool Nappy Covers: Construction, Performance and Which Suits Your Routine

What Is PUL and How Does It Work?

PUL stands for polyurethane laminate. The fabric starts as lightweight polyester, and a thin layer of polyurethane is bonded to one side during the lamination process. That bonded film is what makes the cover waterproof. The quality of that bond matters: a well-made PUL cover holds up to regular washing and daily wear, while a weak bond can peel or delaminate over time.

Because PUL is a barrier rather than an absorbent layer, it holds moisture inside the nappy until change time. That makes it very effective at containing mess. We have single layer and sandwich PUL – the only difference is the layers.

Sandwich PUL (Plain Colour fabrics) – means the waterproof membrane is hidden between two layers of the polyester fabric so it feels slightly thicker than the single recycledPUL. This has been our main PUL for 22 years, but we introduced recycled PUL as an option a few years ago.

Single Recycled PUL (Printed fabric) – means there is only 1 layer of polyester fabric (the outer layer) and the waterproof membrane is attached to that. We used certified recycled polyester for our single PUL – meaning the polyester layer is made from plastic bottles, a common recycling fabric reducing waste.

The trade-off is convenience. PUL is zero maintenance. You wash it with your regular nappy laundry, dry it, and it is ready to go again. No conditioning, no re-waterproofing, no special treatment. PUL also comes in a wide range of prints and colours, so it is easy to build a collection that is practical and fun. For grab-and-go changes, daycare days and busy afternoons at the park, PUL covers are the easiest option. For the full range of PUL options, browse our nappy covers collection.

The main catch is wash frequency. A PUL cover swapped through the day can start to smell musty by evening. Most parents simply rotate covers and launder them with the rest of the nappy wash, and that keeps everything fresh.

What Is Wool and How Does It Waterproof?

Wool covers work on a different principle entirely. Wool is not waterproof in the way PUL is. Instead, lanolin, the natural oil in wool, creates water resistance. When the wool fibres are coated in lanolin, moisture beads up on the surface rather than soaking straight through. At the same time, wool can absorb a surprising amount of moisture before it ever reaches the point of leaking.

That absorbency is central to how wool covers perform. Wool actively pulls moisture away from the nappy and away from bub’s skin. A PUL cover traps moisture at the nappy, whereas wool draws it out and at the same time acts as a waterproof layer. That difference is why many parents trust wool to keep heavy wetters drier through long stretches of sleep.

Wool is also highly breathable. Unlike synthetic covers or disposables, wool lets air circulate around bub’s skin, which helps regulate body temperature and reduces the risk of nappy rash. It is thermoregulating, meaning it keeps bub warm in winter and cool in summer. That is something PUL cannot replicate.

There is no need to layer a PUL cover over a wool cover at night. Wool is designed to absorb and wick moisture on it’s own, so adding PUL on top only traps the moisture that wool would otherwise draw away from bub.

For many families, the most appealing part of wool is how rarely it needs washing. Wool is naturally antibacterial, so it does not need to be washed as often as PUL. In fact many parents wash wool covers only every three to four weeks, and the wash itself is gentle. Between washes, covers need re-lanolising periodically to maintain their water resistance. It is a different rhythm to PUL, but for those who embrace it, wool quickly becomes a firm favourite. If you would like the deeper detail, we have a full guide to how wool covers work.

PUL vs Wool Nappy Covers: How They Perform Side by Side

Once you understand how each material works, the practical differences become clear. The table below compares PUL and wool across the factors that matter most to parents.

Two things stand out from that comparison. First, PUL wins on effort: it is ready to use, easy to wash and needs no special care. Second, wool wins on natural performance: it breathes, absorbs, wicks and regulates temperature. The question is not which fabric is better, but which set of qualities you need at any given time of day.

Which One Should You Choose?

There is no single winner in the PUL vs wool conversation. Every parents routine is different, and every bub’s skin is different, so the right cover will be different too. It often comes down to the time of day and the kind of changes you are doing.

If you want grab-and-go convenience, PUL is the obvious choice. It is ideal for daytime, daycare and warm weather, where quick changes matter more than overnight absorbency. PUL requires no prep, no maintenance and no lanolising, and it is kinder to the budget upfront. PUL Covers can be used over disposable nappies, flat nappies, terry nappies, or any style of cloth nappy.

If your priority is overnight reliability, heavy wetting or sensitive skin, wool is hard to beat. Wool covers absorb and wick moisture away from bub, which makes them exceptional for long sleeps. They are also a natural fit for eco-conscious households that want to reduce synthetics, and the breathability in cooler months is a genuine comfort win. The trade-offs are the higher upfront cost and the periodic re-lanolising care routine.

The honest answer is that many families use both. A few PUL covers for daytime and daycare, a couple of wool covers for overnight and weekend naps. That way you get the convenience of PUL and the natural performance of wool, without locking yourself into one approach. It is the most flexible way to run a cloth nappy routine, and it is why both materials have earned a place in the Baby Beehinds range.

If you are still deciding, look at your typical day and pick the cover that fits the most challenging part of it. You might be surprised how quickly the right choice becomes obvious.

Frequently Asked Questions

Is PUL or wool more waterproof?

PUL is more waterproof in the technical sense, because the polyurethane laminate creates a solid barrier that holds liquid inside. Wool is water-resistant rather than fully waterproof, but because it absorbs and wicks moisture away, it handles heavy wetting without leaking for long stretches. That is why many parents find wool performs beautifully overnight, even though PUL is the more literal waterproof barrier.

Do wool nappy covers need extra care?

Yes, wool covers require a different care routine to PUL. You only wash them every three to four weeks, and the wash must be gentle. They also need re-lanolising periodically to maintain their water resistance. That sounds like extra work, but in practice it means less laundry overall, and wool’s natural antibacterial properties keep it fresh between washes.

Can I use PUL covers overnight?

You can use PUL covers overnight, and many families do. The cover will hold moisture, but because PUL traps moisture at the nappy rather than absorbing it, bub’s skin can feel wetter by morning. If your bub is a heavy wetter, a wool cover may serve you better because it absorbs and wicks moisture away, helping bub stay drier through long sleeps.

Why do wool covers cost more than PUL?

Wool covers cost more because natural wool is a more expensive material than the laminated polyester used in PUL, and the manufacturing process is more involved. For many parents, that higher upfront cost is balanced out by wool’s durability and its very low wash frequency, which means less wear and less water and energy used over time.

Is PUL breathable?

Yes, but PUL is far less breathable than wool. The polyurethane laminate that makes it waterproof also traps heat and moisture, which is why wool is generally the better choice for night time whereas wool, by comparison, is highly breathable and thermoregulating, keeping bub warm in winter and cool in summer. If breathability is a priority for sensitive skin or warm weather, wool is the more comfortable option.