Arcteryx Proton LT Vest Review




Last year we reviewed the excellent Arcteryx Proton LT Hoody. The Proton range of insulated garments fall into Arcteryx’s ‘highly breathable’ insulation range. These garments are intended to worn when active and not as a ‘belay jacket’ type of seal out the elements affair. The Proton LT Hoody had proved an excellent winter layer when the temperatures dipped well below freezing so I had high hopes for the Proton LT Vest. I was not disappointed.

First off vests, gilets, waistcoats, call them what you want, have never quite gained popularity in the UK to the same extent as you see on the continent or even it would appear North America. One take on this I recall from a customer back in the early 90s half jokingly asking why buy a jacket that’s missing its sleeves. Fair point but it also misses the point a little. A gilet (I’m going with the French here) provided essential core insulation whilst allowing complete mobility for your arms. This is especially useful if you’re layering up when winter climbing as although your torso doesn’t suffer too much flexibility loss with an extra layer by the time you’ve got base layer, mid-layer, extra insulation layer (ie. ProtonLT Hoody) and then shell jacket your shoulders and arms can begin to feel a little bound up – not good news if you’re fighting against the layers when swinging your axes! Gilets have always been popular with cyclists, XC skiers and runners as a way of adding core warmth without restriction they’re also a favourite of fashion shoots looking for that rugged outdoor mountain look (my favourite is here – a mere £1265 and it doesn’t look half as good as the Proton LT!).

proton_vest - 1
The Proton LT Vest works brilliantly as mid layer insulation when winter climbing (which is more than can be said for Richies ‘tache!)

A quick summary of the Proton LT’s features; materials wise you are getting a shell made from Permeair™ 2and Fortius™ Air 40 together with Coreloft™ Continuous 65 insulation. The cut is ‘alpine’ specific so geared towards climbing and active mountain pursuits, trim but with complete mobility. Weight wise my small came in at 224g. There are two hand-warmer pockets that sit just above a harness and a small external chest pocket that will comfortably take a smartphone and wallet. Dual hem adjusters seal the waist.

In Use

I’ve been using the Proton LT Vest all winter both as a serious outdoor layering piece and everyday outwear. Much like the Proton LT Hoody this is a versatile garment but I would have to say even more so. Being a gilet means it layers better under the typical kit you use in UK winter climbing, it’s lighter and also packs smaller than its sleeved sibling so can come along in the pack for those occasions when it proves a bit chillier than expected either when climbing or as an addition on belays. Being sleeveless also means it’s easier to get on and off when wearing gloves etc and although it has it’s limitations due to the air permeability of the shell it can make a handy leader’s belay layer if you’re moving swiftly. Alongside this it looks very smart and to be honest it has had lots of wear travelling to and from the mountains and as a warm layer in the car from the hut to he start of the approach. I’m usually wearing just a base layer and a windproof type shell for winter walk-ins and it’s great to have the Proton LT Vest on when you’re stood around lacing up winter boots, sorting poles etc before ditching the Proton LT Vest either back in the car or stuffing it quickly into a corner of your pack, again being sleeveless makes this even easier.

Proton LT Vest – great for smartening up on the food stop home after a day on the Buachaille!

The Proton LT Vest will go on again for the journey home to add an air of respectability at food stops or the pub, keep a beanie in the Proton’s pocket to cover up your helmet hair and all is good 😉 When wearing it whilst active the breathability is excellent for this type of garment and the fact that your arm pits are exposed means it can dump heat well but be aware that if you wear it has part of a layering system with a hard-shell or soft-shell over the top it will seal the heat in and temperatures will climb.


  • Breathable
  • Rugged
  • Light and compact


  • Not a lot.

SRP £150

RiCGR_RichMugchie is the enthusiastic amateur of the team. Enjoying all aspects of climbing but especially alpine, winter and his local grit . Having managed to survive the vagaries of both fluorescent Koflachs and rainbow tights in the 80s he looks forward to an even more stylish future. A shady past in mountain marathons and adventure races, including the Marathon des Sables, means he’s an advocate of fast and light. Though the former is debatable if you’ve seen him on a tricky lead!

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