Synthetic insulated jackets offer reliable warmth in wet weather, compressibility and a long-lifespan. Here's what to look for and the best options out there.
The best synthetic insulated jackets are those that are dependable and that will see you through the rough stuff. The first synthetic insulated jacket that I purchased did just that. It was a Mountain Equipment Fitzroy Jacket and it was one hell of a thing. Fit to burst with PrimaLoft insulation, it lived in the bottom of my climbing pack only to be pulled out during cold, wet and windy winter climbing belay stances that you so frequently find up in the Highlands.
The bombproof, heavy and warm style of the Fitzroy was the trend when I bought my first synthetic jacket – it was built to last in the ‘ming’ that you’re so often blessed with in Scotland and it did the job extremely well. To be honest, synthetic insulation was the piece of equipment you purchased because you knew you had to, not because you wanted to – oh how things have changed with recent developments in synthetic fibres.
Synthetic insulation is made from polyester that has been spun into filaments that creates a pocket of air between each fibre. This pocket then warms up from your body temperature and thus, provides warmth. This is exactly the same way natural down can be used to keep you warm.
Down versus Synthetic
We’ve not yet quite mastered a like-for-like synthetic alternative to down – its formation is just too unique – and so there are still some downsides (sorry) to synthetic insulation in comparison to it. That being said, there are also some upsides to using synthetic insulation over down.
Down offers the better warmth-to-weight ratio over synthetic insulation materials. Put simply, the unique 3D structure of down creates what is called loft which traps air more effectively than any synthetic fill in production at the moment. We could reach a point soon where synthetic insulation will be able to match up though. PrimaLoft is a good example of a type of fill that is getting very near to hitting that same warmth-to-weight ratio.
Wet weather performance
Down doesn’t have a natural ability to repel water (on a goose or duck it’s protected under larger, oily feathers), and so, if it gets wet it will clump together, lose its loft and in turn fail to trap warm air. Synthetic insulation on the other hand won’t collapse when it gets wet to the same extent as down, so in wet conditions you can still count on some insulation value. Bear in mind though, that these days it’s possible to treat down with a solution that gives it hydrophobic properties – so it’s hard to say outright that synthetics are better in wet weather than down! The debate rages on…
Plucking a helpless goose/duck of their lovely insulating down isn’t a very nice thing to do. Fortunately, many reputable outdoor brands these days (though not all of them) take measures to ensure that the down they use is responsibly sourced. This is an argument explored in our best down jackets test.
On the flip side, many are concerned about the impact of synthetic fibres on the environment – they’re normally made from plastic after all. To address this issue, brands like Polartec and PrimaLoft have managed to develop fills that can be recycled. There’s also a fully biodegradable and recycled fibre called PrimaLoft Bio which is now available in some jackets. With these developments in mind, the scale is perhaps tipping in favour of synthetics on this front.
OM Editor Will has taken a range of jackets out with him in Snowdonia and the Brecon Beacons. I took a bunch up to the Highlands and the Alps during some ski touring weekends. Many of the items featured here were actually good enough to be selected for our Green Gear Guide and Outdoor 100, meaning they past our gear team’s rigorous selection processes.
Best Overall Synthetic Insulated Jacket: Black Diamond Vision Hybrid Hoody
Best Value Synthetic Insulated Jacket: Keela Talus
Best Synthetic Belay Jacket: Arc’teryx Nuclei
Best Breathable Synthetic Insulated Jacket: The North Face 50/50
Best Lightweight Synthetic Insulated Jacket: Patagonia Nano Puff
Best Overall Synthetic Insulated Jacket
Black Diamond Vision Hybrid Hoody
Price: €280 Weight: 430g Best for: climbing, backcountry skiing, hiking and hillwalking Key attributes: breathable, durable
This is a hugely innovative jacket, one that’s designed for people who need insulation while partaking in high aerobic activities like backcountry skiing, alpine climbing and hillwalking. The idea is that it provides the insulation you want when you’re slowing down and the breathability and ventilation you want when you’re working hard, ultimately saving you from having to take the jacket on and off all the time.
To achieve this, Black Diamond haven’t just deployed the lightweight, warm-when-wet qualities of PrimaLoft Gold, but they’ve also added a touch of Aerogel – that’s right, the stuff that NASA developed to put into their space suits. The silicone-based solid material is incredibly insulating but it’s also super light. In fact, 99.8% of its volume is empty space and is regarded as the world’s lightest solid.
What’s more, this is designed to be hard-wearing too, with a Liquid Crystal Polymer used in the high abrasion areas of the jacket (the red panels pictured). The same material that’s used in Kevlar – the stuff that bulletproof vests are made from – the LCPs in the fabric here essentially creates synthetic fibres that have an extremely high tear strength and resistance to scuffing and fraying.
As for the features, you’ve got two harness-compatible zipper hand pockets, internal drop pockets for gloves, zippered chest pockets, a neat single pull helmet compatible hood, and elastic cuffs. Heat can also be trapped within the jacket through a handy integrated ‘hem gasket’. That’s essentially an extra bit of fabric that drops below the hem and features its own elasticated hem as a way to prevent drafts of air travelling up through the jacket.
Insulation: 60g PrimaLoft Gold with Cross Core Aerogel / Outer: 20D Nylon with Liquid Crystal Polymer ripstop and a 20D stretch nylon / harness-friendly pockets / stow pocket / zippered chest pocket / internal drop pocket / elastic cuffs / toggled hood / available in S-XL.
Weight: 600g Best for: hiking, hillwalking, mountaineering Key attributes: durable, warm, excellent value
The Keela Talus is a great value jacket, one that’s perfect for anyone who tends to venture into cold and wet places. It features 60gsm of PrimaLoft Gold synthetic fill, bringing lightweight warmth and insulating performance even in wet conditions. What’s more, at least 50% of this fill is made from recycled content, more specifically, plastic bottles diverted from landfills.
Then there’s the outer shell fabric which is both lightweight and durable thanks to the Cordura fibres that make up the ripstop thread within it. Stretchy fleece-lined panels then line the sides of the torso and under the arms to add a bit of extra comfort and to aid the overall temperature regulation as well.
Features include an external zipped pocket on the chest, a zipped pocket on the inside and then two handwarmer pockets which are large enough to take an OS map. There’s also elasticated cuffs, an adjustment on the hem in the form of a glove-friendly cinch and an adjustable hood. Speaking of the hood, this has a malleable wired peak to keep the rain off your face and it’ll fit comfortable underneath a climbing helmet.
60gsm PrimaLoft Gold synthetic insulation / insulation made from 50% recycled content / summer and winter compatible / Cordura ripstop fibres in the outer / stretchy fleece-lined panels on torso sides and underarms / external zipped pocket on chest / zipped pocket on inside / two handwarmer pockets / elasticated cuffs / adjustable hood with malleable wired peak
Price: £315 Weight: 510g Best for: aerobic activities in cold weather Key attributes: breathable, warm, innovative
This is the first instance of The North Face’s 50/50 technology being used with a synthetic fill. All previous designs used down. The baffle design and fabrics, from what we can tell, are largely unchanged too. The baffles all hang off the inside of the jacket with large spaces between them and the materials are all light, slightly stretchy and they’re air permeable while still being densely woven enough to lock all the fill fibres in securely.
100% recycled nylon is used across the arms while the nylon used across the body is 89% recycled. Then there’s the Thermoball insulation which is made from 100% recycled polyester derived from post consumer content – stuff like plastic bottles and packaging.
Details on this jacket include stretchy cuffs that can be pulled over mountaineering gloves, a simple, non-adjustable hood that can be worn comfortably underneath a helmet, a zipped internal pocket on the chest, and there are two handwarmer pockets that contain toggles for the hem adjustment. The jacket can also be packed up into its left pocket.
PFC-free durable water-repellent treatment / 100% recycled nylon across arms / 89% recycled nylon across body / 100% recycled Thermoball polyester insulation / baffle design / stretchy cuffs / non-adjustable hood / zipped internal chest pocket / two handwarmer pockets / packs into left pocket.
The new-and-improved Nano Puff jacket now uses PrimaLoft’s innovative 100% post-consumer recycled polyester insulation made with P.U.R.E. (Produced Using Reduced Emissions) technology. It’s still the same high-performance 60gm PrimaLoft Gold Eco fill used in previous iterations, but with even less impact on the environment. Specifically, this innovative process reduces carbon emissions by a whopping 70% by altering the way the synthetic fibres are bonded together.
The Nano Puff also has a 20-denier 100% recycled polyester shell and lining, while the jacket is Fair Trade Certified sewn. And of course, it comes with all the traditional benefits of synthetic insulation – it offers decent warmth for weight, it’s hard-wearing and compressible, and boasts excellent moisture resistance.
The feature set is relatively simple but practical. It includes a full zip with a soft chin guard, two zipped hand pockets and an internal zipped chest pocket. There are elastic-bound cuffs and a hem drawcord. The hoody version also includes a snug elastic-bound hood. The fit is fairly accommodating, and if you hover between sizes, we’d tend to recommend going for the smaller size. But all in all, it’s a very comfortable jacket to wear.
Light and packable / 20-denier 100% recycled polyester shell and lining / 60gsm PrimaLoft Gold Insulation Eco made with 100% post-consumer recycled polyester / lower carbon footprint due to P.U.R.E. technologies / PFC-free DWR finish / bluesign approved.
Price: £250 Weight: 325g
Best for: belaying, hiking, backpacking, mountaineering
Key attributes: lightweight but warm, lofty
Built for climbers and mountaineers, this is spot on as a belay jacket; it’s the thing that won’t weigh you down or take up much space in your bag when you’re moving fast and light, but then, when you’re paused and your heart rate is slowing, it’s the jacket you’ll want to pull on for that guaranteed warmth, even in wet and miserable conditions.
The fill used in the Arc’teryx Nuclei FL is the brand’s own CoreLoft insulation. In terms of the way it’s structured, CoreLoft is very comparable to Polartec Alpha, its fibres are tangled into pillow-like sheets in each chamber. These sheets all manage to suck in air, giving the jacket a very lofty feel. It doesn’t feel quite as lofty and down-like as PrimaLoft Gold does but then on the other hand, it feels thicker and more durable.
80g of CoreLoft insulation is used in the body and then there’s 60g in the side panels and sleeves, making for an overall warmth that packs a punch. At just 325g overall the Arc’teryx Nuclei FL is by no means a heavy jacket either. One of the main contributing factors here is the outer shell, which is made from a fully windproof 10D nylon with a ripstop weave. It feels very, very thin. Not so thin that you’d need to worry about the fabric on the shoulders when wearing a heavy-loaded pack, but you’d want to be careful picking through any thick brush in it.
Sizes: XS-XXL / windproof / great warmth-to-weight ratio / compressible and packable / durable / water-resistant / trim fit for athletic performance / articulated patterning for unrestricted mobility / gusseted underarms for mobility and comfort / helmet compatible and adjustable hood with soft brim / full front zip with wind flap / elastic cuffs / slight drop hem / two hand pockets with zippers two internal dump pockets
Price: €149 Weight: 624g Best for: casual wear, hiking Key attributes: lofty and warm
Another sustainable offering, this time from Netherlands-based newcomer Cortazu who first burst onto the market with a three-layer jacket made from fully recycled and recyclable materials.
This, the ‘Mid-Layer’ from Cortazu features lightweight insulation to provide a nifty balance between warmth and weight for when you’re working hard. Special props have to go out to that Airtastic outer fabric that offers a good level of stretch and a soft touch, giving it a great level of comfort when worn as either an standalone jacket for warmer climes, or part of a layering system during the cooler months.
This time Cortazu’s sustainability is focused on re-greening farming land for countries in need. For every jacket sold, Cortazu are promising to work with Justdiggit to re-green fifty square miles of what was once fertile farmland at the foot of Kilimanjaro – nothing to dislike about that.
This impressed us for both its lofty, cosy insulation and for its durability. OK, this is primarily made for fishing and country pursuits but we found it holds up superbly as a jacket for hiking and general outdoor activity.
The insulation in this jacket is all body-mapped: your core, arms and head are kept toasty by soft, water-resistant, 45% recycled PrimaLoft Gold Active insulation. We’re huge fans of this stuff here at Outdoors Magic; it’s light, it’s lofty, it’s super warm and it’s also brilliant at insulating even when it’s wet. Then, in the side panels and under the arms, there’s Polartec’s Alpha Insulation (another material that insulates even when wet). This is housed in a stretchy, breathable polyamide which has what feels like a light PU coating on the outside. This adds that durability to the material that we mentioned and it also forms an extra wind and moisture blocking layer.
The jacket is quite thick, so you would only really be able to get a loose and large waterproof jacket comfortably over this. On the flip side, we found that we could wear a light mid layer underneath it without thing feeling tight or restricted.
Finally, as well as two very cosy fleece-lined handwarmer pockets, there’s also a zipped chest pocket that doubles as its stuff sack.
Insulation: 80g PrimaLoft Gold Active (45% recycled content) / 80g Polartec Alpha (55% recycled content) / shell: 20D stretch ripstop polyamide shell / available in S-XXL.
Weight: 470g Price: £125 Best for: casual wear, hiking, backpacking, climbing
Key attributes: lightweight, dynamic, good value
The Phoenix family of well-priced synthetic insulated jackets (Icarus for men) has been around for a few years now. We’ve seen a lightly insulated version, a heftier one, now we have this new one with super stretchy side panels and a nice new Pertex Quantum Eco face fabric. For just £125, you get “active insulation” with this jacket, providing breathable warmth.
This is how it works. There’s narrow baffles and a down-like synthetic fill for warmth, but then big stretchy panels under the arms that will let some hot air escape while also giving you a nice range of movement as well. With all that in mind, it’s going to be climbers who’ll get the most out of this jacket – it’s the kind of thing you could wear on the crag during those colder climbs from early spring through to autumn. But it’ll appeal to backpackers, hikers and bikepackers too.
There are excellent eco credentials. Montane have used a bunch of recycled fabrics in this jacket. You’ve got the outer Pertex Quantum Eco which is made from a 50% recycled polyester, the inner liner which is 100% recycled and then a PrimaLoft Silver synthetic fill on the shoulders and hood that’s made from 100% recycled materials as well. As for features, there’s everything you need: a water-resistant and windproof outer, internal storm flap underneath the main zip, deep hand-warmer pockets and a snug hood which is designed to fit comfortably under a climbing helmet.
Sizes: 8 – 16 women’s / Pertex Quantum Eco 50% recycled outer with DWR / PrimaLoft Black ThermoPlume insulation in the core body and over arms / PrimaLoft Silver 100% recycled insulation in the hood and over shoulders / 100% recycled PEAQ Synthetic Eco lining / insulated under-helmet hood / full-length YKK front zipper with internal storm flap / two zippered hand pockets / pre-elasticated cuffs
Weight: 370g Best for: hiking and backpacking Key attributes: light and packable, excellent warmth-to-weight
The fill Haglöfs have used here is called Mimic. It’s a mix of synthetic fibres that are designed to look like, feel like and perform like down, with the added benefit that they won’t lose their insulating properties when they get wet. These clusters are even blown into the jacket’s baffles following the same process used in down garment manufacture.
There’s more though, because these synthetic clusters also have a graphene filament mixed into them and the benefits of this are actually quite remarkable. Graphene, you see, is a material that’s mainly heralded for its remarkable low-weight, high-strength ratio, but it’s also a super conductor of heat too. That means it’ll take heat from high warmth areas, like your arm pits, and spread it throughout the jacket.
Details include deep handwarmer pockets, an elastic-rimmed hood that’s comfortable underneath a climbing helmet, elasticated cuffs and that’s about it – not much in the way of details but, as they say, Less is More (LIM).
Climate neutral company / 100% recycled polyamide outer and inner fabrics / 100% recycled polyester fill / PFC-free water-repellent treatment / Mimic synthetic fill / deep pockets / elastic-rimmed helmet-compatible hood / elasticated cuffs.
Weight: 350g Price: £225 Best for: casual wear, hiking
Key attributes: sustainably made
Cornwall-based brand Finisterre is an industry leader when it comes to eco-friendly apparel. And one of the most outstanding examples of their sustainable ethos in action is the new Biosmock – a puffy pullover that managed to nab a Gold Award in the Insulation Apparel Category at the 2021 ISPO event.
The Biosmock is a classic insulated smock with a four-button placket that has a fleece-like style but with the warmth and weatherproofing of an insulated jacket. Its outer shell is made from an innovative new fabric called PrimaLoft BIO, a PFC-free synthetic material that is biodegradable on land and in the sea.
Inside that fabric shell is a layer of insulation made from HD wool, a compound of natural sheep’s wool and PLA (polylactic acid, a plastic made from corn starch or sugar cane). It’s also fully biodegradable, while the wool itself is renewable, fully traceable, ethically produced and sourced from farmers who have signed up to eco schemes to improve biodiversity, soil health, natural irrigation systems and carbon sequestering.
ISPO gold winner / PrimaLoft BIO PFC-free fabrics / biodegradable /HD Wool Active Insulation / no zippers / placket and kangaroo front pocket with press studs / water soluble, compostable and recyclable packaging.
Weight: 473g Best for: high aerobic activities Key attributes: sustainably made
The Outdoor Research Shadow Hoody is a synthetic insulated puffer that is sustainably crafted with recycled and bio-based materials, but also comes in muted contemporary colours and looks pretty stylish. However, when you need technical performance, it’s also cosy and packable, offering excellent warmth for weight.
The headline material here is OR’s VerticalX Eco SR insulation. This combines Repreve recycled polyester fill with Sorona, a renewable plant-based fabric that is particularly hard-wearing. The result is a highly compressible fill that offers excellent warmth for weight, a soft down-like feel and good performance even when wet.
The jacket’s hood is insulated and adjustable for an easy fit. An elastic drawcord hem and elastic cuffs with thumb loops hold things in place as you reach, stretch, and move around, whether you’re on the mountain or off it. There’s also plenty of mechanical stretch in the fabric itself. Combined with a soft feel, it makes for an exceptionally comfortable, easy-wearing jacket.
VerticalX Eco SR insulation / bluesign approved 20D nylon and elastane blend for outer fabrics and linings / insulated and adjustable hood / elastic drawcord hem / elastic cuffs with thumb loops / two zipped handwarmer pockets / interior stash pocket.
Weight: £78 Price: 350g Best for: casual wear, hiking and backpacking
Key attributes: good value, sustainably made
The Teca Cálido jacket has been built with sustainability in mind, with a shell that’s made from a repurposed polyester taffeta and a fill that’s 100% recycled polyester.
This insulating performance is helped by a snug, elastic-bound hood, hem and cuffs plus two cosy handwarmer pockets and it’s packable enough to stuff inside its own chest pocket.
This thing’s reversible too. On one side you get that funky colour-blocked design with two zipped handwarmer pockets and then on the other you get more muted navy styling, with square stitch-through baffles, a zipped chest pocket and two drop-in lower patch pockets.
Colour-blocked design / face fabric panels and shell made from repurposed taffeta with DWR finish and PU backer / 60gsm 100% recycled polyester stuffing / elastic-bound hood, hem and cuffs / two handwarmer pockets / stuffs inside its own zipped chest pocket / certified B-corp / 1% of brand revenue goes towards charitable initiatives / reversible / square stitch-through baffles / two drop-in lower patch pockets.
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