Which Arc’teryx jacket should I buy?

So you are looking for a high-quality jacket made from technical materials to wear out in the cold. Well, if you have been in the store or looked into outdoor gear, you may have at least heard of Arc’teryx®. To answer which Arc’teryx jacket to buy, you need to describe its primary use case. In the meantime, we will be highlighting our favorite insulated jacket from Arc'teryx and a few similar options that we carry. And along the way, you may come to appreciate the Atom LT Hoody the same way we do at the Native Summit.

Atom LT Hoody

The Atom LT Hoody is not a puffy jacket, strictly speaking, but it does behave like one. The sleek and trim design makes it perfectly suitable for backcountry use and about-the-town activities. Our staff wear it around the shop in the winter, as spectators to outdoor sporting events, or out on backpacking trips in the Colorado Rockies. As if by some strange coincidence, at least half of the Native Summit staff own an Atom LT Hoody.

Water and wind resistance and a warm but low-profile layer of Coreloft™ Compact insulation make this jacket ideal for chilly days in the fall and spring or freezing days in winter with additional layering. Even when it gets wet, it will stay insulated until you get to your shelter to dry out. If you want to remain dry, throw a rain jacket over the top. This also traps more heat inside the Atom. Plus, it is designed for high-output activities. You can wear it on your wild outdoor adventures and not worry about sweating profusely with breathable side panels that stretch and move with you. And no fear of tearing the fabric on twigs and branches as you move along the trail. 

Technical specs:

• Available sizes: XS - XXXL (up to XXL in women’s)
• Weight: 11.3 oz (women’s small), 13.2 oz (men’s medium)
• Fit: Trim: Slim through chest, waist, hip, and thigh for a low profile fit (Other fittings from Arc’teryx: Regular, Relaxed, Next-to-Skin)
• Hip-length hem
• Insulation: Coreloft Compact
• Outer fabric: Water-resistant Tyono™ 20
• Insulated hood (also available in the non-hooded jacket and a vest)
• Fit Guide for Men and Women

The Atom’s Family

The LT in Atom LT Hoody stands for Lightweight. And it certainly is light. But there is an even lighter option with slightly less insulation in the body and no insulation in the sleeves. 

The Atom SL is more of a windbreaker than a jacket. The SL comes in full-zip, pullover, and vest options. It is still water and wind-resistant, but it would serve better as a mid-layer if you wish to stay warm on frigid days. 

On the other end of the spectrum is the Atom AR. The AR is a few ounces heavier than the LT regarding the hardier, more breathable Tyono 30 outer shell, the slightly larger helmet-compatible hood, and packing in more Coreloft insulation that is loftier than the compact insulation in the LT. The AR stands for All-Around with the intent that this iteration of the Atom is more capable in a more expansive range of conditions.

What are some other options?

The Proton LT is almost the same jacket as the Atom LT. The main differences are the more breathable fabrics in the Proton and the slightly dropped hem and raised pockets in the Proton. The Atom LT and Proton LT are the same weight and use similar versions of Coreloft insulation. The Proton LT exists with climbing in mind. Protons are highly breathable for intense activity. They flex and move with the climber while still providing full coverage. It also comes in an FL, or Fast & Light, option that would not warm you on the coldest winter day but would be perfect for summer summiting and rock climbing.

Is Arc’teryx just not your style? Need something with a little more windproofing? There are several worthy options we enjoy. They also have the more traditional puffy jacket look to them. The Patagonia Nano Puff® comes in a full-zip or pullover as well as hooded and non-hooded jackets. If it is wind protection you are after with the same amount of warmth as the Atom LT (but a little less ventilation), then this option is the one. The Nano Puff is windproof, meaning as the wind blows, it will not pull your body heat out of the insulation in the jacket. The outer shell will block the wind from passing through.

Are you an ultralight backpacker in need of a synthetic insulation piece? The Nano Puff might work for you, but its lighter cousin, Micro Puff®, would be the ultimate weight saver from Patagonia. You sacrifice a little bit of durability in overall construction simply because the material is lighter and thinner than the Nano. But the Micro Puff is 3.5 oz lighter than the Nano Puff, packs down a little smaller, and accomplishes the same environmental protection.

Similarly, the ThermoBall™ Eco from The North Face® is puffy and packed with insulation. Although, it is marketed as wind-resistant, not windproof. But it is a slim fit like the Atom LT. The TBall jacket and the nano puff both have an integrated stuff sack in the chest pocket for packing away your jacket. The Micro Puff can be folded away into the left-hand hip pocket.

Factors to consider

Not all insulation is created equal. But it does all have its merits. So far, we have only touched on jackets containing synthetic insulation. Within the category of synthetic material are different types of insulation. 

Continuous filament synthetic insulation is a single sheet of material that does not shift or bunch up inside a jacket. The entire surface area of the insulation will trap heat. Synthetic fiber clusters are small bits and pieces of insulation that would fall to the bottom of the jacket if not sewn into their own smaller pockets. Insulation is less effective if there is less empty air between fibers. There ends up being no space for your body heat to fill up inside more compact materials.

The Atom LT uses a continuous filament called Coreloft that happens to be very fluffy and perfect for trapping heat in the space between its fibers. The ThermoBall Eco jacket is named after its ThermoBall insulation of the synthetic fiber cluster variety. The 2.5 square inch quadrants all over the jacket house the synthetic insulation. 

The amount of insulation is going to affect warmth as well. Mass per area or grams per square meter provides a measurement for synthetic insulation.

Atom LT Hoody - 60 g/m² Coreloft Compact - 13.2 oz total jacket weight

Proton LT Hoody - 80 g/m² (body), 60 g/m² (arms) Coreloft Compact - 13.2 oz

Nano Puff Jacket - 60 g/m² PrimaLoft™ Gold - 11.9 oz 

Micro Puff Hoody - 65 g/m² PlumaFill - 9.3 oz 

ThermoBall Eco Jacket - 118 g/m² ThermoBall Eco - 9.5 oz 

While the ThermoBall may look like it has the warmest insulation, it uses less material, so it ends up being on the same warmth level as the other jackets. Additionally, the inner and outer fabric of the ThermoBall Jacket is connected directly via a sewn-through stitching technique. There is no insulation, aka no added warmth, in the seams.

Down Insulation

Arc’teryx and other labels we carry in our store also use natural insulation materials. The most popular being goose down. Nothing on Earth quite matches the weight to warmth ratio of down while remaining a feasible clothing option. It is also compressed down easily and helps save space when filling a suitcase or backcountry pack.

Fill-power is how down strength is measured. It refers to how much down is required to fill a certain amount of space under a certain amount of pressure. In simpler terms, how lofty or fluffy down is.

The Cerium LT is another specialized mid-layer or standalone layer from Arc’teryx that provides roughly the same warmth capability as the Atom LT. It utilizes an 850+ fill-power goose down, making the jacket lightweight and highly compressible. One unique aspect of the Cerium LT is that it is not 100% down insulated. Down insulation tends to clump together and lose its insulating properties when wet. To prevent this from occurring, Arc’teryx has placed synthetic insulation in the underarms, hips, cuffs, and shoulders that are zones more likely to get wet or face high amounts of abrasion. 

In summary, there are nearly innumerable types of jackets for every situation. If you are looking for an all-around, cold-weather piece that you can dress up or down depending on the weather and social setting, our favorite is the Atom LT Hoody from Arc’teryx. But even Arc’teryx offers several jackets that could fit that description. That means there are many more options from all the companies we present in the store that get the job done: raincoats, snow jackets, windbreakers, alpine shells, and fleece layers. It is up to us to help you find your ideal match.