Synthetic Insulated Jackets Comparison Review

Down jackets are ideal for stuffing in your pack and puffing out for a blast of warmth when needed. No man has ever made a fibre more warm for its weight and packable. But goose underfluff has its limitations, of course. Where man-made insulation does effortlessly outdo down is in its versatility.

First patented in the 1940s as an alternative to heavy layering or hypothermia, down jackets quickly took off amongst climbers and walkers. They've broadened their horizons over the years and are now available in a vast range of weights down to floaty 'sweaters'. However, one major element prevents them taking over the world of insulation: water. Down has a disconcerting tendency to shrink away when faced with sweat, rain, snow or anything else wet. OK, nowadays many down jackets have water resistant face fabrics, and water resistant down is in the pipeline... but sometimes it doesn't rain it pours. Or drizzles incessantly. In a worst case, you're left shivering in an empty shell, with the dregs of what looks like a cat's coughed up furball in each channel. Water resistance isn't their only limiting factor, either: sometimes even a down sweater proves too warm in our moderate climate, and the Michelin Man stitching required to keep the down in place and lofted adds bulk.

Meanwhile synthetic insulated jackets have evolved, too, keeping well ahead of the game in the versatility arena. When they first became popular, because they offered something important that down didn't - warmth when wet - they were called 'belay jackets'. New technologies and designs have allowed 'belay jackets' to become much more than that. They morph seamlessly from well-fitting mid layer to outer layer as the temperature/weather/speed/activity requires. They are less bulky than down jackets, much lighter than fleece for the same warmth, and they offer much more weather resistance than either down or fleece. Here follows a look at a few popular synthetic insulated jackets currently available in the circa £150 price bracket.


The Patagonia Nano Puff £140

Running on the Pembrokeshire Coast Path  © Huw Davies
The Nano Puff: casual fit and easy to chuck on
The Nano Puff is a flimsy, whimsy, kitsch looking thing, with shiny fabric reminiscent of a Quality Street sweet wrapper. It's a trendy item: Patagonia were almost immediately gleefully labelling the Nano a 'cult classic' when it launched in Winter 09, and it's snowballed into a range. As well as the full zip you can get a quarter zip pullover, hoody, vest and even a Nano Puff scarf. So is the Nano just a fad for the cool kids on the hill?

First off, I zipped it on and went out for a run on the Pembrokeshire Coast Path. I was pretty well protected from sea breezes but could barely feel the Nano's presence over my base layer. The filling is top quality, low bulk, ultra compressible PrimaLoft One (60g/m2), which traps heat very efficiently for its weight. The 'quilt pattern' stitching makes this jacket feel less bulky than any of the others tested (all have 60g/m2 fill, apart from the heftier TNF Redpoint Optimus).


Patagonia were almost immediately gleefully labelling the Nano Puff a 'cult classic' when it launched in Winter 09, and it's snowballed into a range

Patagonia say the stitching increases durability too - however I've had some of these jackets for over a year and have found the build quality of them all superb. None show significant wear or tear. The Nano's outer shell is DWR-treated, so it's water resistant. As I wore it more, I found it kept showers out. When it really chucked it down I got drenched, but the jacket did keep its warmth remarkably well even so.





  • Quilt pattern holds insulation in place promoting durability and longevity
  • Pockets: two zipped handwarmers
  • Drawcord hem
  • Shell: 15 denier recycled polyester (DWR finish)
  • Insulation: 60g/m2 PrimaLoft One polyester
  • Lining: 22 denier recycled polyester
  • Recyclable through the Common Threads Recycling Program
  • Weight: 300g

More info on Patagonia website

Style wise, you have to be quite cool to pull it off - and I didn't. "The diamond stitching pattern and shiny fabric make it look like a kid's jacket and red doesn't suit you," said my friend, when I asked her honest opinion. It does look like it's wearing me rather than the other way around.

Despite the drawback of looking like a walking sweet wrapper, I've reached for this jacket more than any other for activities close to home: walks, bike rides, cragging afternoons and as a booster layer at the climbing wall. I reckon the real beauty of the thing is that it's so easy to chuck on. The fit is casual rather than performance and the styling is simple. A one-way zip, a drawcord hem, elasticated cuffs and two handwarmer pockets with almost invisible zips. Nothing else to see here.

It's completely unrestrictive, too. The shiny lining glides smoothly over a base layer, offering a hit of warmth that's more cosy than your favourite woolly jumper, and feels featherlite. My friend chucked it down from the top of a crag and it floated like a leaf. It works well in a layering system: taking the place of a lightweight fleece but offering more fluffy comfort factor and more wind resistance.


This one's easy to chuck on and essentially like a very practical (and trendy!) jumper - warm, wind resistant, light, still warm when wet. It is quite expensive considering the simple styling though.



The Arc'teryx Atom LT £150

Arc'teryx Atom LT on Mt Longonot in Kenya  © Shan Latcham
Walking the crater rim of Mt Longonot in Kenya

I've had my Atom since Winter 09 - current available colours are Black, Magenta and Bondi Blue in women's. It also comes in a hooded style (365g), vest (193g) and a heavier 'SV' hoody style (412g) in both men's and women's. Yes, this is another jacket that's become a 'classic' and developed into a range ... but more of a Gucci classic than a cult one, like the Nano.

Fussier than the Nano but still clean cut, the Atom has plenty of well thought out features. I can imagine Arc'teryx's designers painstakingly perfecting details such as the stretchy cuffs. Silky smooth and stitched into the sleeve asymmetrically; these maintain a perfect, comfortable fit when you move your hand or grip with your fingers, without allowing snow, rain or wind to creep in, and slip effortlessly under a glove or outer jacket. They make great wrist gaiters without adding the bulk of a thumb loop.


Fussier than the Nano but still clean cut, the Atom has plenty of well thought out features. I can imagine Arc'teryx's designers painstakingly perfecting details

I got a matching Arc'teryx beanie with my jacket and, when they first arrived, headed out in the Peak where I effortlessly pulled off the 'all the gear and no idea' look, climbing with some stronger-fingered friends in my shiny Gucci gear. The jacket has a strong outer face - a 20 dernier tightly woven nylon called 'Luminara' - suggesting Arc'teryx have prioritised durability. It withstood grit, wind and showers well. However I did find the Polartec Power Stretch fleece side panels, which extend from hem to armpits, let in drafts and drizzle when the jacket was worn as an outer layer.

The Atom's had over a year of use now and I've found it best suited to athletic movement. When moving continuously, the breathable panels give a welcome airflow under the arms and, because these are stretchy and the jacket has a slight drop tail, you have good mobility and don't expose your back too much when you reach up, forwards or swing your arms. To top it off, the fitted, sleek shape with articulated elbows mean it fits/works well over just a base layer, and is much less noisy to move in than any of the other jackets tested.



Arc'teryx Atom LT  © Arc'teryx

  • Weather resistant outer face
  • Breathable, insulated, lightweight, compressible and packable
  • DWR finish
  • Articulated elbows, gusseted underarms, soft brushed-lined collar
  • Internal chest pocket, two hand pockets
  • Full front zip with wind flap
  • Stretch-knit cuffs
  • Drop back laminated hem
  • Polartec Power Stretch panels
  • 60g Coreloft insulation
  • Weight: 292g

More info on Arc'teryx website

The Atom worked well as a cold weather, high energy mid layer. I found it ideal for ski touring this spring: the breathable side panels mean you don't get too sweaty when it's worn under Gore-tex.

Inside, the insulation is 'Coreloft'. All the other jackets tested are stuffed with Primaloft One, the industry standard, but Arc'teryx like to seek out or pioneer materials that distinguish them as a cut above the other brands. Coreloft is a combination of Primaloft-like short staple fibres and continuous filaments, so it's apparently softer and stronger than Primaloft.

The finer yarns (1 denier) are crimped to help trap air molecules, which in turn help trap body heat, while the larger yarns (3.5 denier) provide loft and resilience from compression. The fibres are also siliconised to help add resistance to moisture and decrease drying time. Despite them having the same fill weight, I did find the Atom a bit warmer than the Nano - but this may also be because the Atom's fitted shape keeps my body heat in.


With its fitted shape, drop tail and stretchy, breathable side panels, this one is ideal for more athletic movement.




The Rab Xenon £150

Sarah Stirling en route to the unpronounceable top of Iceland, Hvannadalshnjukur  © UKC Gear
En route to the unpronounceable top of Iceland, Hvannadalshnjukur © Mick Ryan

One of Rab's best-selling jacket styles year on year is the Generator, an insulation piece which comes in pullover, full zip or vest form. It's understandably popular because it ticks the boxes: simple, warm, light and hard wearing, but it doesn't have the 'wow' factor of the Nano and the Atom. Then Rab showed me a pre-season sample of a new jacket in the making, called the Xenon. It looked like it would rival the others for interesting features, and also offer something different to them, so I nabbed it to test out. That was last summer and it's now available in the shops.


The gossamer thin outer looked like it wouldn't survive a brush with a bramble, but this 10 dernier marvel of fabric technology is one of the lightest, most durable nylons available

First impressions: the sample looked girly and delicate. A glamorous, shiny turquoise head turner of a thing with a gossamer thin outer that looked like it wouldn't survive a brush with a bramble. You can see the outline of seams and the smooth filling of insulation inside. This 10 dernier marvel of fabric technology created by Pertex is one of the lightest, most durable nylons available. After a good few months of use it has doggedly refused to rip when faced with branches, brambles, gritstone edges and the like. The jacket washes like a rag, too: bike grease came out easily to my relief and a scrubbing brush wielded in panic didn't do any damage.

When it first arrived, I took the Xenon on a press trip to hike across Europe's biggest glacier and up to Iceland's highest peak. It sounded exciting, but was mainly a 14 hour drudge, giving me plenty of time to think about how the jacket was working. It's stand out characteristics are definitely its warmth and strength to weight ratios. Despite being lighter, the Xenon is warmer than either the Nano or the Atom. It's only 290g - and it has an indulgent, sumptuous hood that snugly encases your head, zips right up to your nose and fits well under a helmet. In comparison, my hoodless Atom is 292g, and the hoodless Nano 300g (you can get hooded versions of both: 360g for the Nano and 365g for the Atom).


Rab Xenon Jacket  © Rab


  • Weight: 290g
  • Fabric: Pertex Quantum 10 dernier ultralight rip stop nylon outer/lining
  • 60g Primaloft One fill
  • Lycra bound hood
  • 1-way YKK front zip
  • Internal insulated zip baffle/chin guard
  • 2 hand warmer pockets
  • 1 YKK zipped chest pocket
  • Double exit hem drawcord
  • Packs away into chest pocket

More info on Rab website

Over a year of use I've reached for the Xenon most often to use as a summer booster layer/belay jacket, both in the UK and for sport climbing trips abroad. The hood and warmth to weight are major factors in this. It's also puffier than the Nano and the Atom as it has less through stitching, which makes it more comforting to pull on, and it also packs perfectly into it's chest pocket, so you can lob it in your bag or clip it to your harness.

The Xenon has some great features, too. The zipped chest pocket I find useful for putting my ipod, car key, or whatever in. I like the clever fastener ('Kitty Clip') for rolling the hood out of the way, and the zip baffle, which keeps drafts out. The only things I don't like are that the hand warmer pockets don't have zips, and I feel all jacket pockets benefit from zips (It will apparently have zips for A/W 11), and it's noisy to move fast in.


Excellent warmth/strength to weight and a great hood make it an ideal summer belay jacket/ booster layer. Packs into its pocket so you can lob it in your bag or clip it to your harness.



The North Face Redpoint Optimus £139

TNF Redpoint Optimus Jacket  © Huw Davies
Snow mountain-biking at Brechfa Forest

The heaviest and warmest synthetic insulated jacket on the test (500g), the Redpoint Optimus, is also the cheapest. You're getting more jacket for your money, but how does it compare performance wise?

TNF make a vast range of clothing nowadays from high street wear to high mountain. The Redpoint is part of the brand's topline Summit Series range, made for their most demanding athletes to use in the most demanding conditions. Of course the range is also enjoyed by mere punters like me, who like to count on their clothing to behave impeccably so they can get out and enjoy themselves in all conditions without worrying that they'll get cold or wet and uncomfortable.


This is definitely a cold weather jacket. I guess it's main downside is that it's not as versatile as the others on test

This jacket was a Godsend over the winter when the snow piled up in bucket loads. I first wore it on a trip to Tesco in Bangor, where it kept me nice and warm in the freezer aisle, and I discovered it has a snug, insulated hood with a high neck to keep your body heat in. It's the only jacket on test with a two-way zip. I find these things a double-edged sword. OK so it's useful for belaying and venting, but they are much fiddlier to fasten than regular zips and often get stuck. This one is good quality YKK and runs pretty smoothly so far.

The Redpoint's next outing was snow mountain-biking in Brechfa Forest. It doesn't have a drop tail like the Atom; instead going for an all-round longer length, which kept my lower back warm. The sleeves are a good length so they don't disappear up your arm when reaching forward and have smooth cuffs that fit well under gloves. A padded baffle behind the main zip kept drafts out, and it's topped with thicker fabric that doesn't catch in the zip: a good design. The hip pockets are quite small though - difficult to access with winter gloves on - a bit of a faff.


The North Face Redpoint Optimus Jacket  © TNF


  • Alpine fit
  • Hideaway hem cinchcord
  • Jacket stows in internal zip chest pocket
  • Light PU kiss coat for water resistance
  • Napoleon chest pocket
  • Peripheral hood adjustment
  • Seamless yoke and shoulders
  • Soft shell cuffs
  • Two hand pockets
  • Weight: 500g
  • Fabric: 30 dernier 54g/m2 100% nylon with DWR
  • Insulation: 100g/m2 Primaloft One

More info on TNF website

This heavier jacket is best suited to being an outer layer of course, but on a climbing and walking trip to the Cairngorms I found it worked well for me as a cold weather mid layer, too (I get cold easily). It's cut very ergonomically and has a silky lining so it's not at all restricting despite its weight. Some stitching on the body further reduces bulk, and it fitted well under my waterproof. The hood is great - the lycra binding keeps it in place in the wind and a rear cinchcord can pull it back off your face. I wore it under my helmet and pulled the hood of my waterproof layer over the helmet when needed - snug.

The fill is Primaloft One - but 100g/m2 rather than the 60g/m2 found in the other jackets on test - and the outer face is a thick 30 dernier. It provides a strong barrier against the wind and weather, but this brings the obvious downside of reduced breathability. Now we're coming into spring, I'm reaching for the Redpoint less and less - this is definitely a cold weather jacket. So I guess it's main downside is that it's not as versatile as the others on test.


Ideal for winter weather, especially as an outer layer but also as a mid layer if you're a bit nesh (susceptible to cold weather).



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4 Apr, 2011
Only for girlies
4 Apr, 2011
Really? All those jackets have male equivalents don't they? Colour and fit are pretty irrelevant parts of a review (we all have different body shapes and preferences) so what counts is how well the jacket works.
4 Apr, 2011
Thanks - yes all the jackets come in both male and female versions. Cheers, Sarah
4 Apr, 2011
and the review focusses on synthetics that replace a mid layer fleece too so it's pretty limited in the range to choose from, arguably the redpoint should be reviewed along side things like the Fitzroy and Torres not the nano-puff. But still 'tis a respectable run down.
4 Apr, 2011
One of the best minimalist synthetic insulated tops I've used is the Haglofs LIM Barrier pullover, at 265g. Done a lot of cold-weather trail running in it this Winter. Unfortunately they seem to have stopped making it :( Replaced with the Barrier pullover which looks similar, but is a different beast at 370g.
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