Isobaa Merino 200 Long Sleeve Zip Neck midlayer review: one layer for everything
A beautifully simple merino midlayer that works just as well for wild camps as it does weekday wear. Lightweight, breathable, and smart enough for any setting.
Isobaa Merino 200 Long Sleeve Zip Neck Midlayer
Ideal for: Hiking, wildcamping, backpacking, trail running, every day use
Not suitable for: N/A
The Isobaa Merino 200 Long Sleeve Zip Neck is a 237 g midweight merino top made from 100 % 18.5-micron superfine wool. With flatlock stitching, a drop-tail hem and a smooth half-zip, it’s warm, soft, and endlessly wearable. At around £100, it’s pricier than polyester fleeces but cheaper than premium hybrids. Tested from the Thames Valley to the Brecon Beacons, it delivered outstanding breathability, warmth and odour resistance. This is a versatile piece that transitions from hill to high street without missing a beat — one of the most comfortable and capable merino midlayers we’ve ever worn.
The Good
Super soft merino
Excellent breathability
Smart everyday look
Great under a pack
Odour resistant
The Bad
Pricey for a midlayer
Isobaa Merino 200 Long Sleeve Zip Neck midlayer review
Isobaa might not have the global recognition of Icebreaker or Smartwool, but this small UK-based brand is quietly building a reputation for doing merino right. Their focus is on natural fibres, minimalist design and everyday wearability — a philosophy that runs through everything they make, from socks to fleeces. We’ve already reviewed their Isobaa Borg Fleece, which impressed us with its warmth and retro styling. But this Merino 200 Long Sleeve Zip Neck is a different beast altogether — lighter, simpler, and far more versatile.
At its core, the Merino 200 Zip Neck is built for one thing: adaptability. Made from superfine 200 g/m² merino wool, it’s warm enough for crisp mornings on the trail yet breathable enough to wear all day. Weighing just 237 g, it’s light, soft and packable, serving equally well as a midlayer in winter or a base layer in shoulder seasons. The RRP of around £100 positions it at the upper end of everyday midlayers — but it earns that with materials, comfort and craftsmanship.
When stacked against the competition, it holds its ground remarkably well. Compared to the Icebreaker Merino 200 Descender, the Isobaa is simpler — less techy, but softer and more wearable. The North Face Futurefleece edges it slightly for high-output alpine pursuits thanks to its synthetic matrix, but lacks the natural odour control and casual wearability of merino. And while the Helly Hansen Daybreaker Block Microfleece undercuts the lot on price, it can’t compete for comfort or sustainability. The Isobaa sits neatly between them — refined, natural and beautifully versatile.
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How we tested the Isobaa Merino 200 Midlayer
We tested this layer over several months across three distinct adventures. First, a wild camp in the Thames Valley during summer, where it served as an evening jumper once the mercury dropped to around 12 °C. Then a multi-day hike along the Cornish coast — damp, windy, and variable — where it proved its worth both on the trail and in the pub after. Finally, we took it on a two-day overnighter in the Brecon Beacons in early autumn, worn under a waterproof shell by day and as a sleep layer by night. Across all three trips, it stayed comfortable, odour-free and fresh-looking, even after back-to-back wear.
Features and design
The first thing you notice about the Isobaa Merino 200 Long Sleeve Zip Neck is how soft it feels straight out of the bag. Made from 200 g/m² of 18.5-micron superfine merino wool, it’s one of those rare garments that you instinctively pull on and don’t want to take off again. There’s no itch, no scratch — just a smooth, natural texture that feels instantly comfortable against the skin. That comfort doesn’t fade either. After hours of hiking under a loaded pack, it still feels supple and light, not clammy or coarse.
The cut is spot-on. Isobaa’s designers clearly know what makes a good layering piece because the raglan sleeves and flatlock seams combine to give total freedom of movement. There’s nothing to rub when you’re swinging trekking poles or tightening pack straps. The drop-tail hem gives that extra bit of coverage you don’t notice until you lean forward to lace your boots — then you’re glad it’s there. It’s all quietly well-engineered, the kind of refinement that makes the garment disappear once you’re wearing it.
That same design thought extends to the half-length zip. It’s chunky enough to grab with cold hands and slides smoothly even when tugged one-handed. On a steep ascent you can crack it open for airflow; when the wind picks up, zip it high and the stand-up collar hugs your neck without digging in. It’s a tiny detail, but one that turns this from a simple merino top into a year-round companion for Britain’s stop-start weather.
Being pure merino, it naturally wicks away moisture and resists odour — two things we’ve learned to appreciate on multi-day trips. On our Cornish coast walk, it stayed fresh even after long, humid days followed by nights in the pub. That’s the magic of wool: it balances warmth and breathability better than any synthetic we’ve tried, keeping you comfortable when working hard and when winding down.
Fit is another area where this midlayer shines. It’s close enough to trap warmth but loose enough to wear casually, looking just as at home in a café as on a windswept ridgeline. Under a rucksack, it stays where it should — no twisting, no bunching, no hem creeping up your back. It also packs down small, rolling neatly into a side pocket or packing cube, barely tipping the scales in your rucksack.
Durability feels excellent for such a fine fabric. After repeated wears and washes, ours shows no sagging, no bobbling, and no seam wear. The stitching and finishing are as tidy as anything we’ve seen at this price point, which gives confidence it’ll survive years of use.
Of course, being merino, it isn’t windproof — so on blustery summits you’ll still want a shell over the top. But that’s hardly a fault; it’s simply part of the layering logic. This isn’t a piece that tries to be everything at once. It’s a brilliantly executed, beautifully comfortable layer that slots seamlessly into your outdoor wardrobe — and just happens to look sharp enough for the pub afterwards.
How this Isobaa midlayer performs in the UK
The Isobaa Merino 200 handled our unpredictable climate superbly. On warm days along the Cornish coast it breathed well, never feeling clammy or stifling. When the wind picked up, it retained just enough warmth without overheating. In the Beacons, under a waterproof, it balanced insulation and moisture control perfectly — even after being slept in, it didn’t smell or lose shape.
We found it surprisingly versatile as a lifestyle piece too. It looks sharp enough for everyday wear, and because it doesn’t hold odours, it transitions easily from hill to home. It’s one of those rare bits of kit you genuinely want to keep on once you’re done walking.
Isobaa Merino 200 Zip Neck Midlayer FAQs
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It’s warm enough for most of the year in Britain. As a standalone top it works from spring through autumn, and as a midlayer it’ll comfortably see you through winter. It’s not insulated or windproof, but it traps warmth efficiently thanks to the natural thermal properties of merino wool.
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Exceptionally breathable. Merino’s open fibre structure lets heat and moisture escape fast, keeping you dry on climbs and cosy at rest. The half-zip adds adjustable venting, making it even more adaptable for unpredictable UK weather.
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Absolutely. While £100 isn’t cheap, you’re paying for a premium natural fabric that’s soft, odour-resistant, temperature-regulating and sustainable. It’s a long-term investment in comfort — one you’ll wear on-hill, in town and everywhere between.
Isobaa Merino 200 Zip Neck: our verdict
We think the Isobaa Merino 200 Zip Neck is one of the best merino midlayers currently available in Britain. It’s soft, lightweight, breathable and naturally odour-free — and it looks good enough that you can wear it almost anywhere. The £100 price tag reflects its premium fabric and construction, and for those who value quality, sustainability and versatility, it’s money well spent.
What makes it stand out is how effortlessly it slots into everyday life. It’s the layer you reach for on a cool morning walk, wear comfortably under a shell all day, and forget to take off when you’re back home by the fire. That balance of performance and simplicity is rare. Nothing about it feels over-designed or gimmicky — just well-judged, functional details that quietly work.
It’s also a midlayer that encourages you to own less, not more. Because it performs so well across seasons, you’ll likely find yourself reaching for it in spring and autumn just as often as in the depths of winter. The natural temperature regulation of merino means it adapts seamlessly — staying warm when you need it, cooling when you don’t. For the British climate, that’s a genuine advantage.
We’ve tested countless fleeces and technical layers over the years, but few strike this balance between refinement, comfort and practicality. The fit is flattering, the finish feels premium, and it carries that understated look that Isobaa has become quietly known for. Whether you’re layering it for a long hike in Snowdonia, wearing it to work on a frosty commute, or keeping it on for a pint afterwards, it just works.

A 200 g/m² superfine merino layer that nails the balance between comfort, warmth and versatility — a do-it-all midlayer for British conditions.