Helly Hansen Lifa Merino Max half zip baselayer, £75
+ Norwegian brand Helly Hansen are well known for their synthetic baselayers, which are warm, moisture wicking and quick drying. With the new Lifa Merino range, the brand has sought to overcome the one notable drawback of the synthetic layer – its whiff. Gone are the days of the ‘smelly Helly’ – the new fabric combines merino wool with synthetic fibres for excellent thermal regulation without the pong. The Max layers are the warmest in the range. They look great and perform impressively, making them ideal for cool to cold conditions. The half-zip at the neck also aids cooling.
- As the merino wool is placed on the exterior surface of the fabric, it is not as smooth as a pure synthetic fabric, and thus doesn’t slide under other layers quite as easily. Similarly, although flat-lock seams minimise irritation, we were conscious of the seam that runs across the chest panel. And while the overall fit is good, we would have liked just a little more length in the body and arms.
VERDICT: These Lifa Merino Max layers offer a good mix of durability, warmth and comfort, without noticeable odour even after prolonged use. They’re also very warm and look stylish, but try them for fit if you have particularly long arms or a long torso. 4/5
Mammut Trovat Pro half zip baselayer, £80
+ The Trovat Pro baselayer is made from a merino-synthetic blend – Polartec Power Wool. This has a two-layer construction that puts merino fibres next to the skin, and synthetic polyester fibres on the fabric face (the opposite to the Helly Hansen system). As a result, this layer feels soft against the skin and minimises odour, but also wicks well and offers decent durability. The smooth fabric face also means it slides easily underneath other layers. On test we found that it wicks well, though perhaps not quite as well as a pure synthetic layer, though it is warmer.
- The fit is fairly body-hugging, and slightly on the slim side - worth keeping in mind. Expensive too.
VERDICT: A premium baselayer for cool to cold conditions, with excellent all round performance. The price is high, but thanks to the durability of Power Wool, you should get plenty of use from the garment, without the residual odour that is the drawback of many synthetic baselayers. 3.5/5
Sherpa Rinchen half zip baselayer, £40
+ This is a light, quick-drying synthetic layer intended for warmer conditions, making it ideal for UK summer use or travel abroad. Length is generous in the sleeves and body, offering good protection from the sun’s rays, boosted by the fabric’s UPF rating of 40. The neck zip gives additional ventilation, with a nice zip pull design that harks back to the brand’s Nepalese heritage. The fabric also incorporates Polygiene technology , which is a permanent anti-odour treatment, so this baselayer shouldn’t smell even after a few days on the trail.
- Cut is not as close-fitting as some other baselayers, which may slightly impair wicking performance.
VERDICT: A functional warm-weather layer that makes use of Polygiene silver ion technology to counteract the traditional drawback of synthetic baselayers – the fact that they tend to smell pretty quickly. Like many Sherpa products, there are also a couple of welcome little details that help this garment stand out from the crowd. 3.5/5
Icebreaker Cool Lite Strike LS crew, £95
+ Merino baselayers are proven to work in cool and cold conditions, but Icebreaker’s Cool-Lite range is specifically designed for hot weather. They combine ultralight merino wool with Tencel, a eucalyptus-based wood fibre that wicks moisture and inhibits bacterial growth to fight bad odour. Nylon and lycra in the fabric blend also adds further stretch, comfort and durability. So does it work? Yes – wicking performance is really impressive, as good as the lightest synthetic layers. Breathability is further aided by merino mesh panels that offer excellent cooling. As you’d expect from Icebreaker, the cut is excellent too; close-fitting without feeling restrictive, with plenty of lengths in the torso and arms.
- Price is high for a baselayer. If you prefer to wear only natural fibres, be aware that Cool-Lite fabric incorporates a small amount of synthetic nylon and Lycra.
VERDICT: A premium baselayer for warm weather use that offers great breathability and all-day comfort. We’re really impressed with the performance of the Cool-Lite fabric blend. 4/5
Patagonia Capilene Daily Graphic LS T-shirt, £40
+ This super-stretchy, lightweight baselayer is a comfortable t-shirt that is technical enough for outdoor use but easy-wearing and stylish too, with a cool graphic print. The synthetic fabric is made from 100% recycled polyester and is smooth and soft, with excellent wicking performance. It is also treated with Polygiene permanent odour control to combat the bad smell of synthetic baselayers.
- The fit is more relaxed than some baselayers, which may suit you or may not, depending on preference. We also noticed that a seam runs along the top of the shoulder – though this didn’t cause any irritation, it is noticeable when carrying a heavy pack. Note that although made from recycled polyester, the Capilene layers are still a synthetic fabric, rather than a natural fibre like merino wool or bamboo.
VERDICT: A versatile, lightweight layer that straddles the line between technical baselayer and casual long-sleeved T-shirt. We particularly like the slightly looser fit, contemporary cut and stylish graphic print, as well as the strong eco-credentials of the garment (recycled polyester, Fair Trade-certified production and the use of Polygiene technology to help you ‘wear more, wash less’, which saves water). 3.5/5
Finisterre Argo and Pali Merino baselayers, £50
+ Finisterre is a British brand hailing from St Agnes, Cornwall – so unsurprisingly, its roots are in surfing. These merino layers, however, are well suited to outdoor pursuits like hiking and hillwalking. The fabric is a completely naturally-sourced blend of superfine merino wool and Tencel, a eucalyptus-based wood fibre that wicks moisture and inhibits bacterial growth to fight bad odour. As such, these layers are really breathable and naturally antibacterial. They’re also supremely comfortable – one of the softest merino layers we’ve ever worn. Fit is close but not restrictive, with a simple crew neck design and strategically placed shoulder seams that don’t rub. They’re nice and long in the torso and arms too.
- Very little to fault. We only wish the cuffs had thumb loops.
VERDICT: Finisterre’s blend of merino and Tencel fibres results in one of the most comfortable layers we’ve ever worn. It’s also a completely natural fabric that uses responsibly-sourced, traceable merino and sustainable Tencel fibres, demonstrating Finisterre’s strong ethical and environmental focus. The garment itself is a real winner too – great fit, contemporary colours and versatile enough for year-round use. Trust us, you won’t want to take this layer off. 4.5/5
The North Face light long-sleeve shirt, £40
+ A very lightweight synthetic layer that wicks very well and dries fast. It uses hollow-core polypropylene fibres that seem to offer slightly more warmth than you’d expect from such a garment. Flatlocked seams ensure all-day comfort with no irritation.
- Next-to-skin fit is very close indeed. Although marketed as odour-resistant, this layer smells more after prolonged use than a merino or bamboo equivalent. There are no thumb loops, and it only comes in one colour – black.
VERDICT: If you’re a particularly petite woman, you’ll appreciate the trim fit of this layer, as a size XS is very small indeed. Other than that, it’s your typical synthetic layer, with the usual pros and cons – fast-drying, wicks well, but a bit smelly after a while. A good option for ‘done in a day’ mountaineering. 3/5
BAM flatlock zip-neck bamboo baselayer, £45
+ BAM is a British company with a strong environmental conscience that has pioneered the use of bamboo in outdoor clothing. Bamboo grows incredibly quickly, and yields the same volume as cotton from only 10% of the land area. It doesn’t need pesticides or fertilisers, and the fabric is 100% biodegradable. The bamboo fabric used in this baselayer feels luxuriously soft – as soft as fine cotton. That makes for impressive all-day comfort, aided by the fit, which is close without being restrictive. It’s fairly warm too, making this a good option for high-level, exposed terrain. Best of all, this layer is really long in both the arms and body – it’s the longest baselayer we’ve tested. This means draughts aren’t likely to creep up your back, and wrists are well protected from wind (especially since the garment also has useful thumb loops). It doesn’t pong either. Bamboo is naturally odour-resistant, and we found that even after some pretty sweaty walks, this layer still smelled relatively fresh.
- Although moisture wicking performance is good, since the 200gsm fabric is fairly thick, it’s not quite as effective as lighter synthetic or merino fabrics. We also noticed that the metal neck zipper feels a bit cold on your skin when you pull this layer on after a night in the tent!
VERDICT: An extremely comfortable baselayer that is kind on the environment too. We loved the long length and super-soft fabric – this would be our go-to option for chilly spring or autumn walks. It delivers similar warmth to the merino/synthetic blends reviewed here, so represents great value at this price. 4/5
Alpkit Koulin Trail Tee, £21
+ You get a lot of performance for an incredibly low price with the Koulin Trail Tee. It’s made from a breathable, wicking, quick-drying material that’s perfect for hot days, and the inclusion of Polygiene technology ensures it stays odour-free when you work up a sweat. Other nice touches are the little zipped pocket on the back for keys or cash, and the reflective logos that make you stand out in low light.
- The material is very thin, which is great for keeping you cool on hot days but not so great for keeping you warm in cold weather. It’s quite loose fitting too, so not ideal if you like a body-hugging base layer.
VERDICT: As with most Alpkit products, the price is pretty astonishing when you consider the features packed into the Koulin Trail Tee. Perfect for spring and summer walks, or as part of a layering system on colder days. 3/5
Arc’teryx Cerium SL Hoody, £270
+ The lightest down garment in the Arc’teryx range, the Cerium SL hoody uses high quality 850-fill goose down, with synthetic Coreloft insulation in areas that are prone to moisture build-up. This is one way to counteract the traditional drawback of down as an insulator – that it loses its thermal efficiency when damp. It’s a slightly different approach to many other brands, which have instead developed or adopted hydrophobic treatments to create ‘water-resistant down’. Arc’teryx’s approach adds versatility to a garment that is best used as a mid-layer but which can also function as an outer layer in cool, mostly dry conditions. Other features of the jacket support this range of uses – for example, as well as a hood, the Cerium SL has a scooped tail and hem drawcords like a conventional down jacket. Similarly, you get a full front zip with chin guard, elastic bound cuffs, and two zipped hand pockets, one of which contains a stuff sack. Whether used as an outer layer or a midlayer, it is incredibly lightweight and packable, offering much better warmth for weight than any fleece or active insulation piece. Despite its lightweight and almost translucent appearance, the 7-denier face fabric similarly offers more wind-resistance than most insulated layers, and has a DWR finish too.
- The price is high. We also found that unless you fit squarely in Arc’teryx’s slightly unconventional sizing brackets, you’ll find the fit either uncomfortably tight or ever so slightly too loose, particularly around the midriff.
VERDICT: An exceptionally light and packable down jacket that is an outstanding cold-weather mid-layer due to its impressive warmth-for-weight ratio, but which also works as a lightweight outer jacket to throw on at rest stops. The only comparable garment we’ve tested is the Berghaus Ramche Hyper jacket, which has hydrophobic down fill and a slightly trimmer fit, but no hood. As such we’d say the Cerium SL is a more versatile and useful piece. 4.5/5
Montane Icarus jacket, £150
+ The Icarus (women’s Phoenix) jacket from Montane is a synthetic jacket with a difference – it uses PrimaLoft’s new ThermoPlume fill, which mimics the loft and fill power properties of down. Unlike down, however, it boasts better wet weather performance, dries faster if it does get soaked, and also has none of the ethical considerations that surround the sourcing of goose or duck down. ThermoPlume is about as warm as 550-fill power down, which means the Icarus isn’t comparable to the very best down jackets, but it’s still warm enough for most outdoor users. Montane has also put considerable thought into the design and cut of the jacket, with a micro baffle construction for a tailored fit that still permits good freedom of movement. Articulated sleeves are unrestrictive, and it’s very comfortable to wear. It also feels robust and well-made.
- It’s more packable and lightweight than most synthetic jackets, but not comparable to a lightweight down jacket, despite the marketing blurb. We found the zips annoyingly small and fiddly.
VERDICT: A capable all-round insulated jacket, though some will find it too bulky to wear as a mid-layer. It’s fairly well-priced too – and in our book, decent kit that is also affordable is always a good thing. Warm enough for all but the most extreme conditions, and you won’t mind if it gets wet either, which is always a worthwhile consideration in the Great British outdoors. 3/5
Patagonia Micro Puff Hoody, £250
+ Like the Montane Icarus jacket, Patagonia’s new Micro Puff hoody also uses a lightweight synthetic insulation that is designed to mimic the structure and warmth of down, while performing better in wet conditions. This jacket is much lighter though, and in pure weight is almost comparable to the Arcteryx Cerium SL hoody. That gives it an excellent warmth-for-weight ratio, making it an ideal ultralight mid-layer. The lightweight face fabric is fairly windproof, and has also been treated with a DWR coating for some added weather resistance. But there is a caveat…
- The face fabric is fairly delicate, and it would be easy to rip or tear. In terms of outright warmth, it is still not as warm as a high-quality lightweight down jacket (though it will perform better in damp conditions). It’s also expensive.
VERDICT: Impressive warmth for weight for a synthetic insulated jacket, but more delicate as a result. It compresses to a very small size and has an integrated stuff sack in the left-hand pocket, making it a very packable option. One to consider if you’ve got cash to splash on a lightweight, technical mid-layer and think you’ll be out in cold, wet conditions. 3.5/5
Patagonia Nano Air Hoody, £190
+ Soft and comfortable with good stretch for maximum mobility, this is a great mid-layer for active outdoor pursuits. Its stand-out feature is breathability, however – it’s a great ‘put it on, leave it on’ option, even if you tend to run hot. It has two handy chest pockets, two hand pockets and a tidy hood, though the hood cannot be adjusted. Think of it as a warmer, lighter alternative to a fleece.
- It’s not windproof, and chill cuts through quickly. As such the Nano Air Hoody works best as a classic mid-layer worn under a windproof jacket or waterproof shell. We’ve got some concerns about durability, as the face fabric is fairly delicate and prone to snags or abrasion.
VERDICT: A different beast altogether from a more conventional synthetic insulated jacket, the Nano Air Hoody excels as a lighter and more breathable version of a heavyweight fleece. It’s an excellent active insulation mid-layer for strenuous walks, hikes and scrambles. 3.5/5
Montane Hydrogen Direct Jacket, £170
+ This jacket uses Polartec Alpha Direct insulation – a fluffy fleece or pile-type inner that offers lightweight warmth but also optimises breathability. It is certainly soft and comfortable to wear, with a light, airy feel. In many ways, the technology feels like a throwback to the Pertex and pile combinations that were common a couple of decades ago. However, this evolution is more breathable, while still being fairly windproof, weather-resistant and lightweight. It’s ideal for cool to cold weather use when you’re likely to be working (and sweating) hard. The jacket itself fits well, with articulated arms for good freedom of movement, a simple but functional hood and three external zipped pockets.
- Doesn’t deliver the outright warmth of a lightweight down or synthetic jacket, but then it is designed for active, not static, use. Think of it as a lighter and more breathable alternative to a heavyweight fleece.
VERDICT: One of the most versatile ‘active insulation’ layers we’ve tested, the Hydrogen Direct jacket is more robust than many rivals, meaning it makes a viable outer layer in cool but mostly dry conditions, as well as a good mid-layer. It delivers decent warmth-for-weight, and is comfortable and breathable enough to wear throughout the day, even during periods of high exertion. 4.5/5
Rab Alpha Flux Jacket, £140
+ Rab’s Alpha Flux jacket is another example of a new breed of ‘active insulation’ layers that make use of Polartec Alpha Direct, a very light, open weave pile insulation designed to boost warmth whilst optimising breathability. It’s a very effective mid-layer when worn under a shell, with more versatility than a conventional fleece. The fit is trim, but with good length in the torso and sleeves.
- Although Rab call the Alpha Flux a jacket, it’s more akin to a lightweight fleece, though with better warmth-for-weight. It’s not as robust as Montane’s Hydrogen Direct jacket, nor as warm – but it is slightly more breathable thanks to the use of a lighter face fabric and stretch panels.
VERDICT: Lightweight and highly breathable, the Alpha Flux is a great ‘active insulation’ mid-layer. It’s not quite as robust or versatile as Montane’s Hydrogen Direct jacket, but it does offer slightly better breathability. 3.5/5
Outdoor Research Ascendant Hoody, £180
+ The Ascendant Hoody from US brand Outdoor Research is one of a new breed of ‘active insulation’ layers that make use of Polartec Alpha Direct, a very light, open weave pile insulation designed to boost warmth whilst optimising breathability. It’s well designed as a ‘put it on, leave it on’ layer for intense activity, with a comfortable but form-fitting cut that still permits a good range of movement. It’s a very effective mid-layer when worn under a shell, with more versatility than a conventional fleece, but the face fabric is also fairly robust and blocks out light wind and drizzle.
- Little to fault, other than the fact that this is a little bulkier than the Rab Alpha Flux (though comparable to the Montane Hydrogen Direct jacket), and a bit more robust as a result. One feature we weren’t so keen on were the two hand pockets though, which lack zips.
VERDICT: Lightweight and highly breathable, this is a great ‘active insulation’ mid-layer that remains comfortable all day long. Thanks to its robust construction, it also works as an outer layer in cool but mostly dry conditions. Its good warmth-to-weight ratio makes it a much better alternative to a heavyweight fleece. 4/5
Women’s Rohan Spark jacket, £119
+ The women’s-specific Spark Jacket from Rohan uses similar principles to some of the other synthetic jackets in this round-up to create a lightweight and packable insulated garment. With its understated looks, it’s a versatile option for walks from town to country in cool to cold weather, but packs enough punch to be a good insulating mid-layer when worn underneath a shell in more active contexts. As well as a neat-fitting hood, you get two zipped hand pockets, elastic-bound cuffs and an internal chest pocket that doubles as a stuff sack.
- The hem is elasticated but has no drawcord. It’s not quite as technical as the other jackets in this round-up, and as such is neither as light nor as warm.
VERDICT: A very lightweight women's insulated jacket that will do the job for most walkers, either when worn as a light outer layer on cool, dry days or as a mid-layer in more extreme conditions. It’s not as breathable as the dedicated ‘active insulation’ layers, nor as warm as the ultralight down or synthetic jackets here, but is considerably cheaper. It still delivers far more warmth than a fleece of the equivalent weight, and it’s also stylish enough to wear on or off the hills. 3.5/5
Black Diamond Alpine Start Hoody, £125
+ The most unusual product in this line-up, Black Diamond's Alpine Start Hoody is a singular beast, unlike anything else here. It's basically a very lightweight and extremely packable softshell jacket. It offers good wind resistance and impressive breathability. The fit is excellent, with plenty of length in the torso and body, and the in-built stretch in the Schoeller fabric makes this an extremely comfortable garment to wear during active outdoor pursuits, from trail running to mountain scrambling.
- The lightweight design of this piece means it offers little insulation, and limited weather-resistance. The 20-denier face fabric is relatively robust, but won't withstand continued abrasion.
VERDICT: Having tested this hoody in a variety of conditions, we have to say that we wouldn't wear it as a conventional mid-layer. It's best used as a windproof outer layer in blustery but dry conditions, similar to a lightweight softshell or even a windshirt. Layered over the top of a long-sleeved baselayer and/or a lightweight fleece, it comes into its own as a great system for high-level hillwalking, in conditions where wind is a factor but precipitation is unlikely. How often that kind of weather occurs in Britain is doubtful, but that reflects this garment's intended use as breathable, wind resistant protection for alpinists and 'fast and light' climbers. So something of a niche application, though it does that job very well. 3.5/5
Alpkit Griffon Hoody, £39
+ The fleece is the classic outdoors mid-layer, but Alpkit’s Griffon Hoody is more than that. It uses a gridded fleece backer to provide similar warmth to conventional mid-weight fleece without the weight or bulk. It’s also very breathable, resulting in a versatile hoody that makes a great lightweight mid-layer for chilly days, and even works as a stand-alone piece on days when there’s just a bit of a nip in the air. Features are simple, but you get a full-length zip with a little chin guard, a snug-fitting hood, thumb loops at the sleeves and a single chest pocket. The fabric has also been treated with Polygiene technology, a permanent odour-control system to help you ‘wear more and wash less’ (which also saves water in the process – a green thumbs-up).
- Little to fault, especially at this price. It doesn’t deliver the same warmth as the active insulation mid-layers on test here, nor the ultralight down and synthetic insulated jacket we’ve tested, but then, a fleece never will. As a conventional mid-layer the Griffon is simple but effective, though two hand pockets might have been more useful than the single chest pocket.
VERDICT: We defy you to find a more useful fleece than this for 40 quid. It has similar fit, features and performance to ‘power grid’ fleeces from big name brands that hover around the £100 mark. An absolute winner, and we like the contemporary design and colourway too. 4/5
Sprayway Wodan Hoody, £78
+ This stylish fleece hoody mixes modern fabrics with a heritage feel, thanks in part to the retro appeal of Sprayway’s recently reintroduced orange arête logo. We particularly like the asymmetric stretch panel construction and the heathered ‘marl’ look, which make this fleece stand out from the rest. Other features include a full-length zip with a baffle, an adjustable hood and two zipped handwarmer pockets, one of which has a headphone outlet. Performance is pretty good too – it’s comfortable and easy to wear, and as a lightweight fleece the Wodan Hoody offers decent warmth and wind-resistance.
- This is not the most form-fitting mid-layer around, and we would have liked a tad more length in the torso and sleeves for improved coverage.
VERDICT: As a much-loved British brand with genuine outdoors heritage, we were sad to see Sprayway struggling in recent years. However, in terms of both visual appeal and performance, recent products from the new range seem to show a welcome return to form. The Wodan hoody is no exception – this is a well-priced, lightweight mid-layer that is stylish enough to wear on and off the hills. 4/5
Columbia Fast Trek II Full-Zip fleece, £45
+ This classic lightweight fleece is very soft and comfortable. It also features raglan sleeves to minimise seam irritation, two hand pockets and a chest pocket, and a nice stand-up collar. It’s a straightforward fleece with few technological innovations or added features, but is well-priced, fairly warm and comes in a wide range of colours.
- No hood or thumb loops. Fit is fairly relaxed, which some might find a bit baggy.
VERDICT: If you prefer walking gear that is comfortable, uncomplicated and functional, this classic lightweight fleece is a good option. The soft fabric feel makes it feel cosy to wear, and it will do a good job as a mid-layer. 3/5
Columbia Cabanon Creek Hoodie, £75
+ The contemporary colourways, styling and closer fit of the women’s-specific Cabanon Creek Hoodie gives it strong crossover appeal from town to country. Thanks to the use of stretch fabric and a hood, however, the design also permits good freedom of movement and provides added warmth in more technical contexts.
- It doesn’t deliver the same warmth as the other fleece mid-layers tested here, and certainly isn’t comparable to the insulated pieces.
VERDICT: A comfortable, stylish and contemporary women's lightweight fleece that makes a good mid-layer for most outdoor pursuits or everyday wear. 3.5/5
Berghaus Tulach 2.0 Half Zip Fleece, £75
+ Made from a thick marl fabric, the Tulach 2.0 is a good mid-layer option in all seasons. It’s warm enough to wear underneath a waterproof on cold winter walks, and copes well as an outer layer on dry days in spring and summer. It has a tailored fit and doesn’t feel restrictive when worn underneath a rucksack, and the half-zip is unlikely to catch on buckles and straps. The Tulach is Bluesign approved and contains Berghaus’s Colourkind technology – which claims to use 89% less water in its dyeing process than regular fabrics – so it won’t ruin your carbon footprint either.
- The zipped chest pocket is so small it’s hard to know what to put in it and there are no pockets for your hands, nor a hood. And as with all fleeces, wind always seems to find a way through. It’s not the lightest either.
VERDICT: If you’re a fan of fleeces, you’ll be a fan of the Tulach 2.0. It’s warm, comfortable, practical, and looks quite stylish with black or blue designs to choose from. The only issue is the lack of regular pockets! 3.5/5
Rohan Microgrid Stowaway jacket, £70
+ This lightweight full-zip fleece uses a microgrid fabric, creating a ribbed texture that is designed to trap air and therefore boost warmth, without additional weight. It also improves breathability, making this a good all round mid-layer. You also get two zipped hand pockets and a zipped chest pocket, which the whole garment packs away into very neatly.
- Wind penetrates the open-weave fabric easily, and even this advanced fleece can’t offer the same warmth-to-weight ratio as the insulated mid-layers in this round-up. It's lacking a hood.
VERDICT: A stylish fleece that is versatile enough to wear on the hills or in the pub, though you'll need to add a layer if windy. Thanks to its excellent breathability, it works well as a traditional mid-layer underneath a shell, but is packable enough to take off and stuff into a rucksack if necessary. 3.5/5