Arc'teryx Atom Vest

I've had my Atom LT Vest from Arc'teryx for more than eight years, and it continues to perform year-round as a versatile, lightweight synthetic insulated vest, especially for active use. I use the Atom LT as an extra layer of core insulation skiing (nordic and alpine), hiking, camping, and as an everyday layer. It's a mid layer, it's an outer standalone layer, it's an extra layer stashed in a pack. The Atom LT Vest is so useful I bought an Atom LT Hoody when I saw one on clearance in an outdoor store three years ago.

While Arc'teryx's Atom LT Vest has been updated in the eight years I've had mine, the overall design and intent remain the same. As part of the brand's Atom line it's intended to be a "versatile synthetic insulated mid layer with a high degree of weather resistance."

Fit

Available in women's (XS-XL) and men's (S-XXXL) sizes, the Atom LT Vest is a lightweight (LT), low-profile, minimal vest. Arc'teryx classifies it as a trim fit. I have a women's medium and while it's not relaxed, I find it the right size for a mid-layering piece. If you expect to layer more underneath this vest, consider sizing up.

Generally, I wear at most two base or technical layers under mine, and the fit feels right for this use. I also wear mine underneath various puffy jackets and hard shells in colder temperatures.

The Atom LT Vest falls to hip length, and I haven't had any gaping between my pants and tops.  

Construction & Durability

The vest's front and back exterior is a smooth nylon face (Tyono 20) with a DWR (Durable Water Repellent) finish to repel moisture. Arc'teryx describes it as air permeable, but it will fend off winds. I wouldn't wear this vest in steady rain without a raincoat, but it sheds snow and light precipitation as expected. Plus, since it contains synthetic insulation it won't become a soggy mess if it gets wet. 

The side panels are made from a performance stretch polyester for ventilation and movement. I've never felt restricted in this vest, despite its trimmer fit. It moves with you.

I bought my Atom LT Vest eight years ago and it still looks great, with no obvious signs of wear beyond some minimal pilling on the inside of the fleece side panels. I occasionally wash (cold water on gentle cycle) and dry (tumble dry on low heat) it. It's easy to care for and holds up well.

Insulation & Warmth

The Atom LT Vest is not a lofty, puffy insulated piece. It's low-profile, but that's what makes it so versatile as a mid or outer layer. I can wear it as an outer in warmer weather, such as fall hiking, or layer it with other insulation on the coldest ski days without adding significant bulk. 

It's insulated with synthetic Coreloft Compact (60 g/m² ) insulation, which Arc'teryx describes as:

Highly crimped, multi-denier siliconized polyester yarn that has undergone a special process which reduces the thickness of the material by 50%, without reducing its insulation value by the same amount. Lightweight, breathable, thermally efficient 100% polyester fibre.

This insulation at the back and front add a crucial amount of bonus warmth to your core. I've worn my vest over a base layer while hiking in fall, stuffed it into a pack as an extra layer in summer, and worn it skiing in winter down to at least 0°F (probably lower). Also, I don't use it this way often, but on the coldest winter days (in the single digits F or lower), I can use it while running.

This is a low-profile, lightweight vest, so the loft was never high to begin with, but I haven't noticed any discernible difference in loft in mine over the years. Its relatively small size also means I can carry it along in a pack in three-season conditions for extra warmth. 

Pockets

The Atom LT Vest  has three pockets—two exterior hand pockets with zippers and an Internal chest pocket with zipper, for keys, an iPhone 7, or other valuables, which I always appreciate. The current version can also be stuffed into that internal pocket.

Sustainability

The newest version (not mine) contains materials that meet bluesign criteria. It also has a dope dyed lining fabric, which means the yarn is dyed using no water before creating the fabric, reducing chemicals, carbon, pollution, and energy use.

Nitpicks

There isn't a lot to dislike about the Atom LT Vest. Its price is the major drawback, but like other Arc'teryx clothing I've bought, when I recall how long and how often I've used it with no reduction in performance it becomes more affordable. I also bought mine on sale for additional savings.

My only nitpick is that even though this vest is well suited for indoor-outdoor versatility, with a slightly shiny nylon face it can feel like I'm noticeably wearing outdoors clothes when I'm inside. This is a minor style issue for me though.

Similar Atom Products

Arc'teryx has a system behind its product naming, which I find useful. It classifies the Atom line as "versatile synthetic insulated mid layers with a high degree of weather resistance." In addition to this Atom LT Vest, which falls in the middle for warmth, the Atom line also includes:

• Atom SL Vest and Atom SL Hoody—the even lighter superlight/SL vest and hooded jacket with Superlight Coreloft insulation
• Atom LT Hoody and Atom LT Jacket—the hooded and non-hooded jacket versions of this lightweight/LT vest (I also have the hoody)
• Atom AR Hoody and Atom AR Jacket—the warmer All Round/AR jackets with Resilient Coreloft insulation

Conclusion

The Atom LT Vest is expensive, but as mine heads into its ninth year of use it's hard to fault the price. I've now paid $11.55 for each year of wearing it. It is a minimal, versatile, synthetic insulation piece. It layers well with other base layers as well as mid and outer layers and can be used in a variety of combos. It's an incredibly functional addition to year-round layering systems for any hiker, skier, climber, snowshoer, or camper. I'd buy it again, if I ever needed to.

Great extra bit of core insulation for over your base layer or under your main puffy.

I often run really warm while I'm moving, but cool down very fast when I'm done for the day. I often bring only a very thin base layer and windshirt, even when quite cold, and then use a thicker than expected down jacket for when I'm done. I often think of bringing a fleece so I have something for on the move, or for when it gets extra cold to wear with my puffy, but because of bulk and weight I often don't.

Last couple of climbs I have left both the fleece and down jacket at home. Instead I opted to only bring a very thin base layer, an Atom LT vest, and Atom LT Hoody. I would only use the hoody on the move when below -20˚C, but the vest gives me good core warmth in less cold temperatures would it be necessary. In that sense it takes over the role of my bulky fleece. 

During longer rests, or at the end of the day, the Atom LT hoody by itself is often a bit cold for me. I always feel I want to bring just a bit more to be sure. This vest is just that bit more. 

The vest and hoody layer over each other perfectly fine, and this combination is actually easier to put on/off than taking off the Atom LT, putting on your fleece, and putting on the hoody again. I also like that the vest has its own windproof fabric already, and that it weighs less than most of my fleeces. My medium weighs 225gr.  

Dropped back hem, reflective logo, stretch fleece side panels. Hidden hand warmer pockets. 

Fit:

The vest fits like the hoody. If you have a medium in one, I would get a medium in the other. It is fitting but not tight. Because of the power stretch panels on the sides there is some stretch while moving. The back hem is a bit lower so your back is not as quickly exposed when bending over. You can layer either the hoody over the vest, or the vest over the hoody - both fits easily. 

Construction:   

The vest is very well constructed. Perfect stitching and finish, and like the other Atom LT garments the outer shell fabric is very pleasing to the touch. It doesn't stick so much to your skin, and doesn't give you that static charge when putting it on/off. There is no hem cord adjustment, but the fit is good. There are two side hand pockets, and a quite spacious inside pocket. The inside of the neck is a fleece like surface. The front has a reflective logo that might help you to get noticed in traffic lights. 

Fleece side panel finish.

Adjustability:

The zipper is like the other Arc'teryx Atom zippers, non-locking. It can open up on you. This is so you can open it with one hand, which I actually love.

On a recent scramble up a 3000+m / 10.000+ft peak, I knew it was going to be cold up top and that we were going to spend some time there (to watch the sunrise). I was wearing both the Atom LT vest and hoody under my hard shell. When scrambling up I was naturally warming up inside. I opened up the pit zips and the top of the main zipper of my shell, and holding on to some rock could just open up both zippers on my insulation pieces. It's just very easy to adjust this way. 

Moisture:

If I wear the vest while active, I can see some droplets beat up on the outer fabric layer. It is really comforting to be able to wear your insulation on the move. The Coreloft insulation will actually dry itself out if worn under a shell, and even when wet you will stay warm. To be honest I haven't found out to what extend that is the case. I have yet to really soak this piece. So far I have always stayed warm, and have no hesitation to wear this while active - something I never did with my down garments. 

My guess is fleece does perform even better when more seriously compromised, but the Coreloft is not like down in that nothing is left when it gets soaked. If you play in wet and cold environments this is golden. What I like about this over fleece is that it is easier to get on, doesn't require me to put on a separate wind shell, and is a bit lighter and quite a bit more compact when stowed in your pack. 

Overall:

The vest gives me just that bit of extra insulation that I like, for a very light weight and in a very small package. I got it to have just a bit more insulation where a whole other jacket would be too much. As it turns out I wear the vest all the time because it is so versatile. It layers well, and is very easy and quick to take on or off.

Nothing that a fleece and a down jacket don't take care of, but depending on your usage, perhaps a lighter, faster alternative. 

This is the perfect vest! Make sure you try it on store to get the right fit, but it works as a perfect mid layer and an outer layer in slightly warmer weather. I've used it to hike, bike, backpack, sleep, and I even wear it to work as it's a pretty neutral and stylish vest. Overall 5/5.

Warm, durable, packs down small, layers well, looks great with everything.

I love this vest! I wear it all the time.

It's a great layer for keeping my core warm when I need just that extra something, and it fits under most jackets very well. 

The material on the sides and front are different, but both are very durable and soft.

The zipper is nice and stout and the pockets are nice and deep so I can get my whole hand covered and tucked out of the cold. 

Breathable protection.

Phenomenal core protection with a light weight. Outperforms many down vests in both warmth, wind resistance, and breathability. Compare to the Arc'teryx down light vest, I find the Atom LT more breathable and less prone to be wet.

It is my main winter protection while ascending paired with a 260 Merino wool top. It feels very warm and yet breathes condensed air very well. I carry an Atom LT Vest on every hike.

Material is light and durable but a bit on the delicate side. Size runs true. 

Background

Many years of alpine guiding