Arcteryx Phase Base Layer Review

Even the box looks cool!

Even the box looks cool!

Over the last few weeks several members of Taunton Leisure staff have been putting the Arcteryx Phase base layer through its paces on walks, runs and climbs in the wintry conditions of the English outdoors. 

It’s a thermal base layer designed for high output activity in cool and cold weather conditions, such as climbing, hiking, trekking, skiing, snowboarding, as well as for urban and casual use. 

Here you can find out what our staff thought of it. Read on and learn about how the Phase works to keep you warm when you need it, cool when you need it, and always dry…

Arcteryx were formed in North Vancouver, Canada, in 1989. They offer a variety of products focused towards the outdoors and winter sports. A favourite of many of our staff, their products highlight an ethos of no compromise fabric, design and performance.


Steve with the Arc'teryx dummy, fondly known as 'Terry'

Steve with the Arc’teryx dummy, fondly known as ‘Terry’

The key to protecting yourself and staying warm when outdoors is to dress appropriately. I’m not talking about socks and sandals or other fashion ‘faux pas’, but rather adopting the correct approach to what you wear in order to stay warm, dry and comfortable.

The best way to achieve this is to follow what is known as the ‘Three-Layer System’. Wear three layers, each a different type (base layer, insulation/mid layer, outer shell) that work together to each perform a vital function and ensure the user’s comfort, whatever the outdoor activity.

The three layer system works on the scientific principle that heat travels through water much quicker than it does through air, meaning that if your skin is wet it is going to get cold a lot quicker than if it were dry.

To keep the body warm and dry, a high quality base layer must be worn instead of a regular t-shirt, as it will quickly transport or ‘wick’ moisture away from the body, through the fabric. It does this using a highly refined and technical fabric design and construction (which we’ll attempt to explain later!) – your average cotton T-shirt can absorb roughly a third of it’s total weight in water, meaning that when you sweat it will absorb and retain some of that moisture.

The stop-and-go nature of some outdoor activities means that the body will sweat, then cool, then sweat again. A wet cotton t-shirt will only serve to cool you down and can be quite uncomfortable. It compels your body to work harder in an attempt to keep itself warm.

With a technical base layer, you won’t have this problem; ‘moisture management’ (catchy, right?) will ensure that it adapts as you go from an active phase to a rest phase. A good base layer must be lightweight, durable, stay dry as possible and of course, keep you warm.

Enter the Arcteryx Phase base layer range! It comes in a few different shapes, sizes and flavours in either crew or zip neck.

If you’re wondering about their naming system: AR stands for ‘All round’ –  “Provides high performance & weather protection and highlights a range of features to give All Round versatility in multiple activities.

SV denotes ‘Severe’ – “Employs the most durable materials for prolonged use and provides the most weather protection in the harshest weather conditions.” 

Staff Test: The Verdict:

DSCF0185The Arcteryx Phase has been put through it’s paces by a few of our staff. Here’s a bit of feedback from them giving us their impressions of the Phase. First off, Taunton store’s Amanda gives us her experience with the Women’s Phase AR Zip LS:

“We set out for a seven hour walk on a recent cold and wet day having driven about one half hours.

This base layer performed well above any that I have worn previously. You can feel the moisture moving round to the front of the body and then wicking away leaving your back and torso warm and dry.

On getting back to car I usually feel cold all the way home but not any more the difference is huge, I will be getting my second one very soon!”

Nick B, Manager in Exeter, has used the Phase AR Zip while climbing and on various hiking trips.

Crag of the Month (July) - Hound Tor - Part 1“The Phase heats you up well, so well that I’ve not had to use it much in the warmer conditions of the summer. Inside, it’s very comfortable and is bobbly like a fleece, which feels nice against the skin. 

“The way that it’s cut gives really good coverage. The back and arm lengths are generous and the neck line is nice and high, cutting down on exposed skin to keep you warm. 

“You’ll stay warm when stretching because it won’t ‘ride up’ your back; ideal for climbing and skiing where you’re moving a lot and your arms are extended for periods of time.

“It’s an essential bit of kit for cold weather activities. The flat lock seams don’t rub or get in the way and price-wise, it’s surprisingly good value for a premium brand product.”

Stu, also from our Exeter store, outlines further features that make the Phase a great bit of kit.

Stuart and Charlie Enjoy the fine weather at Honeybag“Firstly, it’s really durable. The high stitch count on the seams makes them much less likely to fail. I’ve washed mine several times; it still looks pretty good and hasn’t lost it’s shape or stretched at all.

The antimicrobial qualities are also really effective. I actually wore mine for a whole week without washing it and it didn’t get smelly!!   

I actually think this is the quickest drying baselayer I’ve used. It’s highly breathable and wicks moisture away from the body really quickly.” 

A pretty positive assessment, then. But what about the science?

Arcteryx Phase: The Science:

The Phase uses “Phasic Base Layer Technology” in order to regulate temperature, moisture and comfort effectively in three ways:

  • Hydrophobic non-absorbant yarns transfer water molecules to the high wicking Phi yarns. Encapsulated silver ions eliminate odour. (silver is added to the make-up of the fabric – its antimicrobial properties help prevent odour). The Hydrophonic yarns serve to minimise the moisture retained by the garment, keeping the weight down.
  • During active phases, the multi dimensional Phi yarns wick moisture across the entrie garment for quick evaporation, while also regulating the temperature.
  • The two yarns together create a bi-component structure which enables moisture to be wicked across the fabric during active phases for best temperature regulation and quickly evaporated during rest periods for quick drying, helping the wearer to stay warm.

Courtesy of Arcteryx 

The Phase base layers also feature ‘stretch knit construction’ – eliminating the need for moisture absorbant stretch yarns (aka lycra) and allows the garment to retain it’s shape without sagging.


For those of you out there who couldn’t quite stomach the techy stuff and would like a short, sweet summary of what this garment is all about. Here are the main qualities of the Arcteryx Phase base layers:

  • Suited particularly for start/stop activities e.g. running, hiking, climbing, skiing.
  • Durable – Retains it’s shape, high stitch count.
  • Quick Drying.
  • Moisture management.
  • Well cut – good arm & back length.
  • Comfortable – seams don’t rub, soft against skin.
  • Value – cheaper than merino wool

Generally speaking, synthetics dry much quicker than merino as they absorb less water, they are also more durable. Merino is considered by some, albeit subjectively, to be more comfortable and less likely to smell than some cheaper synthetic base layers, though the Phase appears to buck this trend.This isn’t a comprehensive buying guide to all base layers by any means. We haven’t mentioned the advantages and disadvantages of using merino wool in comparison to synthetic fibres, or looked at the merino wool products that Arcteryx themselves offer. What we have done is to outline the various iterations of the Phase as a highly recommended base layer for outdoor activity of all kinds, one which any of our staff would be confident in recommending. We hope you found it useful!

For a general, but in-depth comparison between the two, take a look at this article from the folks at Backpacking Light. Be warned, the article was published in mid 2006 and things may have moved on somewhat since then!

If you’d like to know more about base layers or have any other questions our staff in store are more than happy to talk with you about them. You can also talk to us via our Facebook,  Twitter pages and also on our website.

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