- Patagonia and Arc'teryx are like up to 70% off at REI rn...
Arc'teryx Atoms vs Protons: Overview
Y'all know this is just my opinion... right?
- Proton Heavyweight vs Atom Heavyweight (aka AR): Perfect picks for cold weather. If I were to buy either one of them, I'd get the new Proton Heavyweight (breathes more, offers much more pockets, more abrasion resistant). If, however, I were to maximize warmth & wind resistance at all costs, then I'd get an Atom Heavyweight.
- View Arc'teryx's comparison of the two: https://arcteryx.com/us/en/compare/X000007302/X000007398
- Proton (aka LT) vs Atom (aka LT): They're very similar. Both are perfect for high output activities and casual use at the same time. Proton offers a bit more abrasion resistance, Atom offers a bit more breathability.
- View Arc'teryx's comparison of the two: https://arcteryx.com/us/en/compare/X000007520/X000007487
- Proton Lightweight (aka FL) vs Atom SL (soon to be called Lightweight): Perfect for high output activities and casual use during chilly spring and summer mornings. Proton Lightweight offers a bit more abrasion resistance and one more pocket. Atom SL is more of an all rounder, offers a bit more breathability and is very slightly insulated only in the body.
- View Arc'teryx's comparison of the two: https://arcteryx.com/us/en/compare/X000006908/X000005409
- View Arc'teryx's comparison of the two: https://arcteryx.com/us/en/compare/X000006908/X000005409
Arc'teryx Atoms vs Protons: Summary
The Proton Hybrid (Men's - Women's - read review) is different than other items. I don't think it belongs in Atom vs Proton comparison, so I won't mention it here.
In order to choose between the other 6 items, I think you should determine the warmth you need first. Refer to the table above for this.
Now you know if you need a Hw, a base or a Lw. And only have to decide between Atom vs Proton.
All Atoms offer a side panel for increased breathability. It doesn't work that well in Atom Hw, but works perfectly with Atom and Atom SL, because their panels are much longer.
All Atoms also come with a StormHood, unlike the Protons that come with a standard hood.
I personally find the Protons a bit more suitable for high abrasion activities. Think lots of climbing, skiing and/or backpack use without a shell.
Atoms, on the other hand, are a bit more suitable for all-round use and/or if you use the hood a lot. Think a combination of a variety of high output activities. It's perfectly fine for climbing, skiing and/or heavy backpack use as well. It's just if you'll do it, say, more than half the time, then a Proton can be more suitable.
Notice where I say "a bit".
The differences between the same line Atom vs Proton might not be that noticeable to you in practice. So if you care about the looks of your jackets as much as their performances, then I don't see anything wrong in going after the prettiest one. Especially if you're planning to use your jacket also around town.
In other words... As long as you get Hw vs base vs Lw right, Atom vs Proton shouldn't matter equally as much.
You might also want to check out this Arc'teryx's Naming Scheme Page as well, which includes both "Atom" and "Proton".
- Poll results: Giant Arc'teryx & Patagoina survey (Gore-Tex, pockets, hoods, fit, & more) [1000+ participated]
- Pics from outrageous discounts I ran into at Arc'teryx Parndorf Outlet
- I bought Gamma Lightweight (aka SL), Gamma (aka LT) and Gamma MX
- Patera Parka (one year update): Ain't worth the price...
- Alpha vs Beta: I bought all 4 Beta's and both Alpha's. Settling this for good
- I visited Iceland again, this time with a Nuclei (aka FL)
- Proton Hybrid: A "hidden" way to stuff it in itself!?
- Best Insulated Jackets: A hands-on Arc'teryx & Patagonia face-off
- 2024 Nano Air is in! Bought it immediately...
- I bought all 7 of Winter '24 Atom and Proton jackets
- Best Arc'teryx Ski Jackets: Rush is ideal, Sabre SV is overkill
- Arc’teryx colors: Most and least liked (poll results)
- Took my Nuclei SV to the Alps near Pfander, Austria
- Arc'teryx Alpha Parka Review: The most impressive jacket of all time
- Arc'teryx ReGEAR: OutdoorCrunch exclusive promo code!
- Beta Insulated Jacket is in: Pit zips AND two way zipper
- DropHood vs StormHood: Pros/cons and best uses
- 7 things all Arc'teryx newbies should know
Like hauntingly dark yet brilliantly brilliant electronic music? Check out my Hidden Electronic Gems playlist at Spotify.
- Macai Shell: https://arcteryx.com/us/en/shop/mens/macai-shell-jacket
- Nita: https://arcteryx.com/us/en/shop/womens/nita-down-jacket
- Epsilon: https://arcteryx.com/us/en/shop/mens/epsilon-insulated-hoody
- Cerium Pants (yes, seriously): https://arcteryx.com/us/en/shop/mens/cerium-pant
- Liatris: https://arcteryx.com/us/en/shop/womens/liatris-down-jacket
- Thorium SV: https://arcteryx.com/us/en/shop/mens/thorium-sv-hoody
- Proton Heavyweight: https://arcteryx.com/us/en/shop/mens/proton-heavyweight-hoody
- Atom Shacket: https://arcteryx.com/us/en/shop/womens/atom-shacket
- New Nano Air: https://patagonia.com/product/mens-nano-air-insulated-hoody/84367.html
Naming changes
After changing the names of some women's jackets last season (Fall/Winter 2023), this season Arc'teryx moved on to make the same changes for men's counterparts as well.
- Atom AR → Atom Heavyweight (in short, Hw)
- Atom LT → Atom
- Atom SL → Atom Lightweight (in short, Lw; and the change has not yet took place for men's counterparts)
- Proton LT → Proton
- Proton FL → Proton Lightweight (in short, Lw)
- Proton Heavyweight and Proton Hybrid are new.
Changes are exclusive to the naming and fit. Structural designs remain the same. The fit is being updated universally, for all Arc'teryx jackets.
Name | Activity | Breathability | Weather Res. | Durability | Temp (F/C) | Bottom line | Review | Pit zips? | Two way zipper? | Stuffs into itself? | Hood? | Face Fabric | Fit | Weight | Length | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Alpha FL (Men's - Women's) | Climbing | 7/10 | No data | No data | 10/10 | N/A | No | No | Yes | Hadron 3L Gore-Tex | Trim | 209 g / 7.4 oz | 76.5 cm / 30 in | Yes | |||
Alpha SL (Men's - Women's) | Climbing | 5/10 | 7/10 | No data | 9/10 | N/A | No | No | Yes | N40p 3L Gore-Tex | Trim | 326 g / 11.5 oz | 77.5 cm / 30.5 in | Yes | |||
Alpha (aka AR) (Men's - Women's) | Climbing | 8/10 | 9/10 | 8/10 | 4/10 | N/A | Go-to climbing harshell. | Review | Yes | No | No | N40d & N80d Most Rugged 3L Gore-Tex Pro | Regular | 430 g / 15.2 oz | 79.5 cm / 31.25 in | No | |
Alpha SV (Men's - Women's) | Climbing | 8/10 | 10/10 | 10/10 | 3/10 | N/A | Strongest climbing hardshell. | Review | Yes | No | No | N100d Most Rugged 3L Gore-Tex Pro | Regular | 510 g / 1 lb 2 oz | 78 cm / 30.75 in | No | |
Alpha IS (Men's) | Climbing | 7/10 | 5/10 | No data | 8/10 | 23/-5 | No | Yes | Yes | N40p-X 2L Gore-Tex | Regular | 610 g / 1 lb 5.5 oz | 78 cm / 30.75 in | Yes | |||
Beta (Men's - Women's) | All Round | 6/10 | 7/10 | 7/10 | 8/10 | N/A | Streamlined all-doer shell. | Review | No | No | No | N30p-X 3L Gore-Tex | Trim | 300 g / 10.6 oz | 76 cm / 30 in | No | |
Beta Lightweight (Men's - Women's) | All Round | 8/10 | 7/10 | 7/10 | 6/10 | N/A | Review | Yes | No | No | N40p 3L Gore-Tex | Fitted | 380 g / 13.4 oz | 75 cm / 29.5 in | No | ||
Beta LT (Men's - Women's) | All Round | 7/10 | 7/10 | 8/10 | 6/10 | N/A | Review | Yes | No | No | N40d 3L Gore-Tex | Fitted | 395 g / 13.9 oz | 76 cm / 30 in | No | ||
Beta AR (Men's - Women's) | All Round | 8/10 | 9/10 | 9/10 | 4/10 | N/A | Go-to all-round harshell. | Review | Yes | No | No | N40d & N80d Most Rugged 3L Gore-Tex Pro | Regular | 460 g / 1 lb | 76 cm / 30 in | No | |
Beta AR StormHood (Men's - Women's) | All Round | 8/10 | 9/10 | 9/10 | 4/10 | N/A | Review | Yes | No | No | N40d & N80d Most Rugged 3L Gore-Tex Pro | Regular | 460 g / 1 lb | 76 cm / 30 in | No | ||
Beta Coat (Women's) | All Round | 6/10 | 5/10 | No data | 5/10 | N/A | No | Yes | No | 3L Gore-Tex | Regular | 320 g / 11.3 oz | 88 cm / 34.5 in | No | |||
Beta Insulated (Men's - Women's) | All Round | 9/10 | 7/10 | 8/10 | No data | 21/-6 | Go-to hybrid jacket. | Review | Yes | Yes | No | N40d 2L Gore-Tex | Regular | 680 g / 1 lb 8 oz | 78.5 cm / 31 in | No | |
Beta Insulated Coat (Women's) | All Round | 7/10 | No data | No data | No data | 16/-9 | No | Yes | No | N40d 2L Gore-Tex | Regular | 600 g / 1 lb 5.2 oz | 86 cm / 34 in | No | |||
Beta Down Insulated (Men's) | All Round | 9/10 | 7/10 | 8/10 | No data | 0/-18 | Yes | Yes | No | 2L 40D Gore-Tex | Regular | 760 g / 1 lb 10.8 oz | 79 cm / 31 in | No | |||
Beta Long | All Round | 4/10 | 9/10 | No data | 3/10 | N/A | Review | No | No | No | N80p 3L Gore-Tex | Regular | 441 g / 15.6 oz | 85 cm / 33.5 in | Yes | ||
Beta LT Hadron | All Round | 7/10 | 6/10 | 4/10 | 5/10 | N/A | No | No | No | Hadron 3L Gore-Tex | Fitted | 255 g / 9 oz | 76 cm / 30 in | Yes | |||
Beta SV (Men's - Women's) | All Round | 8/10 | 10/10 | 10/10 | 3/10 | N/A | Strongest all-round harshell. | Review | Yes | No | No | N80p-X Most Rugged 3L Gore-Tex Pro | Regular | 495 g / 1 lb 1.5 oz | 79 cm / 31 in | Yes | |
Gamma Lw. (aka SL) (Men's - Women's) | All Round | 7/10 | 2/10 | 6/10 | 5/10 | N/A | Review | No | No | No | Fortius 1.0 | Trim | 310 g / 10.9 oz | 74 cm / 29.1 in | No | ||
Gamma (aka LT) (Men's - Women's) | All Round | 7/10 | 3/10 | 7/10 | 3/10 | N/A | Go-to softshell. | Review | No | No | No | Wee Burly Double Weave | Regular | 545 g / 1 lb 3.2 oz | 76 cm / 30 in | No | |
Gamma MX (Men's - Women's) | All Round | 6/10 | 4/10 | 8/10 | 3/10 | N/A | Strongest softshell. | Review | No | No | No | Fortius 2.0 | Regular | 555 g / 1 lb 3.6 oz | 74 cm / 29.1 in | No | |
Sabre SV (Men's) | Skiing | 10/10 | 10/10 | 10/10 | 1/10 | N/A | Strongest ski jacket. | Review | Yes | Yes | No | N100d Most Rugged 3L Gore-Tex Pro | Regular | 595 g / 1 lb 5 oz | 85 cm / 33.5 in | No | |
Sabre (Men's) | Skiing | 8/10 | 8/10 | 7/10 | 2/10 | N/A | Review | Yes | No | No | N80p-X 3L Gore-Tex | Regular | 705 g / 1 lb 8.9 oz | 79 cm / 31 in | No | ||
Sabre Insulated (Men's) | Skiing | 7/10 | No data | 6/10 | No data | No data | Review | Yes | No | No | N80p 2L Gore-Tex | Regular | 815 g / 1 lb 12.7 oz | 76 cm / 30 in | No | ||
Rush (Men's) | Skiing | 8/10 | 9/10 | 9/10 | 3/10 | N/A | Go-to ski jacket. | Review | Yes | No | No | N80p-X & N100p-X 3L Most Rugged Gore-Tex Pro | Regular | 590 g / 1 lb 4.8 oz | 79.5 cm / 31.25 in | No | |
Rush Insulated (Men's - Women's) | Skiing | 3/10 | 5/10 | 5/10 | 9/10 | 16/-9 | Review | No | No | Yes | Hadron 2L Gore-Tex Infinium | Regular | 515 g / 1 lb 2.2 oz | 79 cm / 31 in | No | ||
Macai Shell (Men's) | Skiing | No data | No data | No data | No data | N/A | Review | Yes | No | No | N80p-X 3L Gore-Tex | Regular | 775 g / 1 lb 11.3 oz | ? | No | ||
Macai (Men's) | Skiing | 7/10 | 7/10 | 6/10 | 1/10 | 5/-15 | Review | Yes | No | No | N40p-X 3L Gore-Tex | Regular | 990 g / 2 lb 2.9 oz | 75 cm / 29.5 in | No | ||
Macai Lightweight (aka LT) (Men's) | Skiing | 7/10 | 7/10 | 6/10 | 2/10 | 8/-13 | Review | Yes | No | No | N40p-X 3L Gore-Tex | Regular | 855 g / 1 lb 14.2 oz | ? | No | ||
Theriss Down (Women's) | Skiing | 7/10 | 6/10 | 7/10 | 2/10 | No data | Review | Yes | No | No | N80p 2L Gore-Tex | Regular | 709 g / 1 lb 9 oz | 63 cm / 24.8 in | No | ||
Sentinel (Women's) | Skiing | 8/10 | 7/10 | 7/10 | 2/10 | N/A | Go-to ski jacket. | Review | Yes | No | No | N70p 3L Gore-Tex | Regular | 640 g / 1 lb 6.6 oz | 73.7 cm / 29 in | No | |
Sentinel Insulated (Women's) | Skiing | 8/10 | No data | No data | No data | 21/-6 | Review | Yes | No | No | N80p 2L Gore-Tex | Regular | 600 g / 1 lb 5.2 oz | 79.8 cm / 31.5 in | No | ||
Sentinel Relaxed (Women's) | Skiing | No data | No data | No data | No data | N/A | Yes | No | No | N80p 3L Gore-Tex | Regular | 655 g / 1 lb 7.1 oz | ? | No | |||
Sidewinder (Women's) | Skiing | 8/10 | 8/10 | 7/10 | 2/10 | N/A | Yes | No | No | N80p 3L Gore-Tex | Regular | 570 g / 1 lb 4.1 oz | ? | No | |||
Andessa (Women's) | Skiing | 10/10 | No data | No data | 1/10 | 8/-13 | Yes | No | No | N40d 3L Gore-Tex | Trim | 869 g / 1 lb 14.7 oz | 67 cm / 26.4 in | Yes | |||
Andessa Shell (Women's) | Skiing | 5/10 | No data | No data | 3/10 | N/A | No | No | No | N70p 3L Gore-Tex | Trim | 560 g / 1 lb 3.8 oz | ? | Yes | |||
Micon Heather | Skiing | No data | No data | No data | No data | N/A | Yes | No | No | NP100-d 3L Gore-Tex | Regular | 685 g / 1 lb 8.2 oz | 83 cm / 32.5 in | Yes | |||
Micon (Men's) | Skiing | No data | No data | No data | No data | N/A | Yes | No | No | N80p 3L Gore-Tex | Regular | 685 g / 1 lb 8.2 oz | 83 cm / 32.5 in | Yes | |||
Cassiar (Men's) | Skiing | 8/10 | 7/10 | 8/10 | 3/10 | N/A | Review | Yes | No | No | N70p 3L Gore-Tex | Trim | 820 g / 1 lb 12.9 oz | 74.5 cm / 29.3 in | Yes | ||
Cassiar LT (Men's) | Skiing | 6/10 | 6/10 | 6/10 | 5/10 | N/A | Review | Yes | No | No | N70p 3L Gore-Tex | Trim | 605 g / 1 lb 5.3 oz | 75 cm / 29.5 in | Yes | ||
Ravenna (Women's) | Skiing | 8/10 | 7/10 | 8/10 | 3/10 | N/A | Review | Yes | No | No | N70s-4 3L Gore-Tex | Trim | 725 g / 1 lb 9.6 oz | 69.5 cm / 27.4 in | Yes | ||
Ravenna LT (Women's) | Skiing | 6/10 | 6/10 | 6/10 | 5/10 | N/A | Review | Yes | No | No | N70p 3L Gore-Tex | Trim | 540 g / 1 lb 3 oz | 69 cm / 27.2 in | Yes | ||
Procline (Men's) | Skiing | No data | No data | No data | No data | N/A | Yes | No | No | N70p Gore-Tex Infinium | Trim | 720 g / 1 lb 9.4 oz | 76 cm / 30 in | Yes | |||
Shashka Stretch (Women's) | Skiing | No data | No data | No data | No data | N/A | Yes | No | No | N70p Gore-Tex Infinium | Trim | 670 g / 1 lb 7.6 oz | 71 cm / 28 in | Yes | |||
Sabre AR (Men's) | Skiing | 7/10 | 8/10 | 7/10 | 7/10 | N/A | Review | Yes | No | No | N70p 3L Gore-Tex | Regular | 700 g / 1 lb 8.7 oz | 79 cm / 31 in | Yes | ||
Sentinel AR (Women's) | Skiing | 7/10 | 8/10 | 7/10 | 7/10 | N/A | Review | Yes | No | No | N70p 3L Gore-Tex | Regular | 590 g / 1 lb 4.8 oz | 72.5 cm / 28.5 in | Yes | ||
Sabre LT (Men's) | Skiing | 7/10 | 8/10 | 7/10 | 8/10 | N/A | Review | Yes | No | No | N80p 3L Gore-Tex | Regular | 660 g / 1 lb 7.3 oz | 83 cm / 32.5 in | Yes | ||
Sentinel LT (Women's) | Skiing | 7/10 | 8/10 | 7/10 | 8/10 | N/A | Review | Yes | No | No | N80p 3L Gore-Tex | Regular | 565 g / 1 lb 3.9 oz | 73.5 cm / 29 in | Yes | ||
Incendia (Women's) | Skiing | 8/10 | 9/10 | 9/10 | 3/10 | N/A | Review | Yes | No | No | NP100d 3L Gore-Tex | Trim | 610 g / 1 lb 5.5 oz | 79 cm / 31 in | Yes | ||
Indencia IS | Skiing | No data | No data | No data | No data | No data | Yes | No | No | N80p 2L Gore-Tex | Regular | ? | 78 cm / 30.75 in | Yes | |||
Squamish (Men's - Women's) | Running | 5/10 | 4/10 | 7/10 | 9/10 | N/A | Go-to running jacket. | Review | No | No | Yes | 30D Tyono | Trim | 140 g / 4.9 oz | 77.5 cm / 30.5 in | No | |
Norvan Windshell (Men's - Women's) | Running | No data | No data | No data | No data | N/A | No | No | Yes | Permeair 20 | Trim | 90 g / 3.2 oz | 73 cm / 28.75 in | No | |||
Norvan Shell (Men's - Women's) | Running | No data | No data | No data | No data | N/A | No | No | No | 13D 3L Gore-Tex | Trim | 190 g / 6.7 oz | 73 cm / 28.75 in | No | |||
Nodin (Women's) | Running | 8/10 | 5/10 | 5/10 | 10/10 | N/A | No | No | Yes | 20D Tyono | Trim | 130 g / 4.6 oz | 75 cm / 29.5 in | No | |||
Incendo Airshell (Women's) | Running | No data | No data | No data | No data | N/A | No | No | Yes | ? | Trim | 105 g / 3.7 oz | ? | No | |||
Incendo (Men's) | Running | 7/10 | 4/10 | 5/10 | 10/10 | N/A | Review | No | No | Yes | Lumin | Trim | 125 g / 4.4 oz | ? | Yes | ||
Norvan LT (Men's - Women's) | Running | 5/10 | 5/10 | 8/10 | 6/10 | N/A | No | No | No | N13p 3L Gore-Tex | Trim | 190 g / 6.7 oz | ? | Yes | |||
Norvan SL Ins. (Women's) | Running | No data | No data | No data | No data | 39/4 | No | No | Yes | Gore-Tex ShakeDry | Trim | 270 g / 9.5 oz | 71.5 cm / 28.1 in | Yes | |||
Cita (Women's) | Running | 7/10 | 4/10 | 5/10 | 10/10 | N/A | Review | No | No | Yes | Lumin | Trim | 120 g / 4.2 oz | 67.5 cm / 26.5 in | Yes | ||
Cita SL (Women's) | Running | 7/10 | 4/10 | 4/10 | 10/10 | N/A | Review | Yes | No | Yes | Permeair 20 | Trim | 65 g / 2.3 oz | 61.5 cm / 24.2 in | Yes | ||
Incendo SL (Men's) | Running | 7/10 | 4/10 | 4/10 | 10/10 | N/A | Review | No | No | Yes | Permair 20 & Canim | Trim | 80 g / 2.8 oz | 73 cm / 28.75 in | Yes | ||
Norvan SL (Men's - Women's) | Running | 7/10 | 6/10 | 8/10 | 8/10 | N/A | Review | No | No | Yes | Gore-Tex Infinium | Trim | 120 g / 4.2 oz | 77 cm / 30.4 in | Yes | ||
Trino SL (Men's) | Running | 8/10 | 5/10 | 7/10 | 6/10 | N/A | Review | No | No | No | Gore-Tex Infinium | Trim | 340 g / 12 oz | 74 cm / 29.1 in | Yes | ||
Trino SL Anorak (Women's) | Running | 8/10 | 7/10 | 8/10 | 7/10 | N/A | Review | No | No | No | Gore-Tex Infinium | Trim | 290 g / 10.2 oz | 65 cm / 25.5 in | Yes | ||
Solano (Women's) | Around Town | No data | No data | No data | No data | N/A | Review | No | No | No | Gore-Tex Infinium | Relaxed | 355 g / 12.5 oz | 72 cm / 28.3 in | No | ||
Venda Anorak (Women's) | Around Town | No data | No data | No data | No data | N/A | No | No | No | Gore-Tex | Relaxed | 255 g / 9 oz | 75.5 cm / 29.7 in | Yes | |||
Zeta FL (Men's - Women's) | Hiking | 4/10 | 6/10 | 4/10 | 6/10 | N/A | No | No | No | N20r 2L Gore-Tex | Trim | 221 g / 7.8 oz | 76 cm / 30 in | Yes | |||
Zeta SL (Men's - Women's) | Hiking | 3/10 | 5/10 | 4/10 | 5/10 | N/A | Review | No | No | No | 2L Gore-Tex | Trim | 310 g / 10.9 oz | 77.8 cm / 30.6 in | Yes | ||
Zeta LT (Men's - Women's) | Hiking | 5/10 | 7/10 | 8/10 | 5/10 | N/A | No | No | No | N40P-X 3L Gore-Tex | Trim | 335 g / 11.8 oz | 78 cm / 30.75 in | Yes | |||
Zeta AR (Men's) | Hiking | 7/10 | 8/10 | 7/10 | 4/10 | N/A | Yes | No | No | 3L Gore-Tex | Regular | 425 g / 15 oz | 80 cm / 31.5 in | Yes |
Performance data axis of synthetic jackets (table above) and shell jackets (this table) are different. Don't compare them.
- Patagonia and Arc'teryx are like up to 70% off at REI rn...
Arc'teryx Atom Heavyweight (aka AR) vs Proton Heavyweight: Overview
Atom AR has been one of the flagship Arc'teryx products of all time. Been around for more than 10 years. It's a proven, stunning jacket. I've been recommending it left and right.
Proton Hw, on the other hand, is just released for Fall 2023 / Winter 2024 season. But I fell in love with it first time I saw it.
Atom Hw is more wind resistant and a bit warmer. It also offers StormHood. It does offer a mesh panel at the armpits for increased breathability, but it doesn't make that much of a difference in practice. Proton Hw, on the other hand, is more breathable, even though it doesn't offer any mechanical venting. It's also more durable, a bit more water resistant and offers three more pockets than Atom Hw.
Warmth
Atom Hw is warmer by a small margin.
- Atom Hw:
- 120 g/m2 of Coreloft in the body,
- 80 g/m2 of Coreloft in the sleeves,
- 60 g/m2 of Coreloft in the hood.
- Proton Hw:
- 100 g/m2 of Coreloft in the body,
- 60 g/m2 of Coreloft in the sleeves and hood.
But this can be a double edged sword. Because of the fabric of Atom Hw, which is 30D Tyono.
Breathability
Tyono is nylon. It offers poor breathability. That's why Arc'teryx incorporates other Atom models with much larger side fleece panels.
Atom Hw does have a fleece panel too, but it's just too small, it takes place only in the armpit.
Does not make a huge difference. So it's possible to overheat inside the Atom Hw. Wish they offered a two way zipper. I use it a lot with my Nuclei SV.
Proton Hw is noticeably more breathable.
Even though Proton Hw doesn't offer any mechanical venting options, its face fabric Fortius Air 50 allows air permeability much more than Atom Hw's 30D Tyono.
You might also want to pay attention to the possible color differences occur at this area.
I've grabbed mine in Boxcar, so it doesn't have any color differences as you see in the image. But some models like the Gold colorway do.
Hood
Atom Hw offers StormHood, whereas the hood that Proton Hw offers is just the standard one. Additionally, Atom Hw also offers inner drawcords to tighten and cinch the hood as you wish.
Pockets
Proton Hw absolutely destroys Atom Hw in this department.
Atom Hw offers two hand warmers and one internal chest zippered pocket.
The chest pocket is mid-small size. I can fit my iPhone easily in there.
Proton Hw, on the other hand, offers two hand warmers, two external zippered chest pockets on each side, and two internal dump pockets. Dump pockets never add to the weight of the jacket that much either (no zips). So it comes almost at no extra energy cost. Which is great.
That makes three more, or in other words double the number of pockets in Atom Hw.
Pocket dimensions are as follows:
- Atom Hw:
- Hand warmers: 6.7 in (or 17 cm) x 9.4 in (or 24 cm)
- Internal zippered chest pocket: 7.5 in (or 19 cm) x 10.6 in (or 27 cm)
- Proton Hw:
- Hand warmers: 9.1 in (or 23 cm) x 8.3 in (or 21 cm)
- Internal dump pockets: 7.9 in (or 20 cm) x 8.3 in (or 21 cm)
- External chest pockets: See image.
I love more pockets. Did you see this Arc'teryx fan by the way? Hilarious.
Durability
Proton Hw has over the edge.
The difference between Proton Hw and Proton (aka LT) is bigger than the difference between Atom Hw and Atom (aka LT) in this regard.
Proton Hw has a burly face fabric. It's not unusual for a 50D face fabric to outshine a 30D in this regard.
Weather resistance
Both are very well extremely weather resistant. But Atom Hw has the edge over Proton Hw.
Atom line, and the Tyono outer face fabric, is particularly well resistant against wind. When talking about the Atom (aka LT) and Atom SL, it's a different story, because they let the wind in thorough their side fleece panels when your arms are up.
But in the case of Atom Hw, these panel only takes place in the armpits. They're not exposed most of the time. They're not equally as light either.
Both are DWR coated and waterproof.
DWR is a coating.
It's basically sprayed on to the surface of these jackets as a finish.
It stands for Durable Water Repellent - which means that water will be repelled under wet conditions instead of soaking into the fabric.
DWR also decreases dry time.
It's a good thing these jackets are coated in DWR.
But pay attention to the fact that DWR is a coating - meaning that it will wear off over time.
Which is why you might want to invest in a DWR spray such as this one at arcteryx.com for after treatment.
As you see, there's a strong correlation between FP x FW and temperature ratings, but not more than, say, 80%. I explained why this happens here in this post of mine.
Cuffs
Cuffs are similar.
Sleeve length is the same.
Fit
Both come in revised fit.
I'm 5'11", 165 lbs, athletic build. Size M fits me perfectly.
My size is always the same. Arc'teryx, Patagonia, TNF, Salomon, Columbia, Nike, Adidas, Under Armour, Zara... Doesn't matter.
Arc'teryx Atom (aka LT) vs Proton (aka LT): Overview
These two are the most popular of all.
I'd recommend you to base your decision when it comes to Proton vs Atom primarily on what you're planning to do with the jacket, your view when it comes to side fleece panels, and lastly, your taste when it comes to the looks.
Because of superior warmth and abrasion resistance capability of Proton, I think that it's mostly the better pick for climbing and skiing in not-so-cold-but-still-chilly days. It also better resists against a heavy backpack.
Atom, on the other hand, is mostly the better choice if you run warm, love side fleece panels for increased breathability or will be using the hood a lot.
Warmth
Both Atom and Proton use Coreloft Compact. But Proton is equipped with 80 gsm of it in the body and 60 gsm in the hood, whereas the Atom is equipped with 60 gsm everywhere.
On top of that, side fleece panels of Atom make a great job in terms of increasing breathability, but in return, this also causes the heat to escape.
Proton also comes with slightly longer hem (center back) length, which makes another noticeable difference in warmth.
Weather Resistance & Durability
The face fabric of Proton (Fortius Air 20) is designed to balance air permeability and weather protection. It's especially convenient where wind and water resistances are required without sacrificing too much breathability. This makes it suitable for active use.
The design of the face fabric of Atom (Tyono 20) is more directed towards compressibility and weight savings. It's fairly breathable but its main objective is wind resistance.
This is why you'll see Atoms being used as wind jackets. They're spectacularly good at this. Atom SL (soon to be called Lw) isn't even insulated in the arms, for example, unlike its corresponding Proton, the Proton Lw (aka FL). It feels like you're wearing an insulated vest + a windbreaker on top of it.
One thing that is worth noting in here is that Atom offers side fleece panels, which can (will) let the wind in and warmth out when your hands are up.
As you see, it isn't possible to make definitive judgements about the weather resistances of these two. Proton is definitely a bit more durable and very slightly more water resistant. But when it comes to wind resistance, I think it depends on the person and the intended use.
Overall, I'd say Proton is a bit more weather resistant. But nothing noticeable.
Also, both jackets are DWR applied.
DWR is a coating.
It's basically sprayed on to the surface of these jackets as a finish.
It stands for Durable Water Repellent - which means that water will be repelled under wet conditions instead of soaking into the fabric.
DWR also decreases dry time.
It's a good thing these jackets are coated in DWR.
But pay attention to the fact that DWR is a coating - meaning that it will wear off over time.
Which is why you might want to invest in a DWR spray such as this one at arcteryx.com for after treatment.
As you see, there's a strong correlation between FP x FW and temperature ratings, but not more than, say, 80%. I explained why this happens here in this post of mine.
Breathability
Had all the other factors been equal (they're not), then Fortius Air 20 of Proton would make it more breathable than the 20D Tyono of Atom - as I explained earlier. Comparing pure membranes in here, back to back.
But even though technology has gone a long way in terms of engineering more breathable and durable fabric (like Fortius Air), mechanical venting still tops it. Ultimately, the side fleece panels of the Atom, which span from the armpits to the hem on both sides, make it more breathable than the Proton.
Side fleece panels of Atom are pretty popular.
Mobility & Comfort
Elastane is what gives jackets the stretchy nature. Fortius Air 20 of Proton involves 16% elastane, where 20D Tyono of Atom involves %6 of it.
Atom, however, has stretchy panels in the armpits, which gives the arms and shoulder more mobility.
A quick recap here, a design that allows more stretching also increases durability.
Stitches experience less stress with it and hence the jackets last more.
I feel better in Proton, but that's because the outer fabric is smoother. It's more fun to wear for me.
In terms of mobility and comfort, I think it's a draw.
Pockets
Unlike other two comparisons (Atom Hw vs Proton Hw & Atom SL vs Proton Lw), this is the only comparison where Proton does not outshine Atom.
In addition to two hand warmers both jackets offer, Atom offers an additional internal zippered chest pocket, and Proton offers an additional external zippered chest pocket.
Below are the pocket dimensions.
- Atom:
- Hand warmers: 10.6 in (or 27 cm) height x 7.1 in (or 18 cm) width
- Internal zippered chest pocket: 9.9 in (or 25 cm) height x 7.5 in (or 19 cm) width
- Proton:
- Hand warmers: 9.4 in (or 24 cm) height x 7.5 in (or 19 cm) width
They're pretty much comparable.
Packability
Neither of these jackets have a pocket that they can stuff into. Wish they did.
Fit
Both come in revised fit.
I'm 5'11", 165 lbs, athletic build. Size M fits me perfectly.
My size is always the same. Arc'teryx, Patagonia, TNF, Salomon, Columbia, Nike, Adidas, Under Armour, Zara... Doesn't matter.
Cuffs
Their cuffs are similar.
Sleeve length is the same.
Historical Revisions
FW24: Atom LT and Proton LT changed to Atom and Proton
Arc'teryx removed the LT from both products in FW24.
They became Proton and Atom. Changes have been exclusive to the naming and fit. Structural designs remain the same.
FW20: Atom LT revision
Not much has changed really.
With the 2020 revision, Atom is given a dope-dyed liner, a new construction on the cuff and is now 1" (2.5 cm) longer.
So, as a result;
- Cuff construction allows for easier on/off and layering,
- Durability is slightly increased now owing to Dope-dyed liner (Dope Permeair™ 20 - 100% nylon) - but the difference is really not noticeable at all.
Additionally, Dope Dying is much more environmentally friendly, so Arc'teryx is also reducing their mark on the planet by incorporating it into the production process.
Transcript of my chat with the customer service
- Hi there! My name is Camille, how can I help you today?
- Hi Camille. I was wondering about the updates that took place for the 2020 revision of Atom LT. Can you list all the changes, please?
- Hi there, thanks for chatting. I sure can.
- The redesign includes an update to the cuff construction for easier on/off and layering, an updated material package for enhanced durability, updated fit, and a dope dyed liner.
- What do you mean by updated material package?
- We updated the materials the Atom LT is made of, you can read a list of them here:
- Coreloft™ Compact (60 g/m² ) insulation. 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.
Tyono™ 20 denier shell with DWR treatment - 100% nylon
Stretch fleece - 94% polyester, 6% elastane
Dope Permeair™ 20 - 100% nylon - Last year's model did not include the Dope Permeair.
- How does it affect the use of this jacket in practice?
- It doesn't effect it, really - Dope Dying is much more environmentally friendly so we are reducing our mark on the planet by incorporating it into the production process.
- Overall the updated Atom saw more changes with the fit, durability and construction on the cuff.
- If anything it's very slightly more durable now.
- Which update made it more durable?
- The additional dope dyed liner.
- Ok, thanks. Lastly, how did the fit change?
- It is about 1" longer than the previous year's model.
- So other than this hem length difference, everything stays the same in the fit department?
- That's right.
FW19: Proton LT revision
Fortius 40 vs 20
In order to increase breathability, designers decided to change the insulation material from Fortius 40 to Fortius 20. In English: Fabric is now slightly thinner but also more air-permeable.
This is measured with a metric called CFM (cubic feet per minute). The new Proton LT has a CFM of 40 compared to the CFM of 20 that belongs to the older version.
Coreloft Continuous vs Compact
Because the Coreloft Compact of the revised (new) version is composed of highly crimped fibers, it's more compressible and air-permeable compared to the Coreloft Continuous of the previous version.
The Coreloft Continous, on the other hand, has more fluff at the beginning (so slightly higher CLO value - which means slightly warmer) but can pack down over time meaning that the jacket will eventually lose some of its fluff and warmth a little bit.
We can say that the warmth didn't really change noticeably (if at all).
Continuous is also more durable since it's less air-permeable.
Since the design intent of Proton LT is a highly air-permeable jacket for high output activity, design team decided to switch to Coreloft Compact for air-permeability and packability reasons.
Compared to the previous model, the most recent (2019) version of Proton LT is;
- lighter,
- more packable,
- more breathable,
- slightly less durable.
Fit remains the same.
Arc'teryx Atom SL (soon to be called Lightweight) vs Proton Lightweight (aka FL): Overview
I wear an Atom SL for mid & high output activities, and a Proton Lw for everything else.
So, if you'll be performing high output activities more than, say, 50% of the time, then Atom SL can be a better option. It's lighter and more breathable. It also has StormHood. Proton Lw doesn't.
Otherwise I'd recommend the Proton Lw. I love its Octa Loft. It's insanely smooth to skin. I love wearing it. Plus you have more storage options. Hand warmers are 50% larger than Atom SL and you get an additional external zippered chest pocket. To me, the hood is also more comfortable when it's not on.
Warmth
Both are lightly insulated and their warmth are comparable.
Atom SL isn't insulated around the sleeves. Only around the torso. This makes it feel like you're wearing a vest and a windbreaker.
Proton Lw is insulated everywhere. Unlike the synthetic insulator Coreloft used in all the other jackets in this round up, Octa Loft is a knitted insulation, like PolarTec. Check out the images below to see what it's like.
Proton Lw is the only Arc'teryx jacket insulated with Octa Loft. It's light and unbelievably comfortable. Enhances mobility and "stretchy" feeling of the jacket too.
Breathability
Side fleece panels of Atom SL make a noticeable difference. I love how much it breathes.
But the breathability of Proton Lw is also top notch, although a bit behind the Atom SL.
In previous versions of Proton Lw (i.e Proton FL), the insulation was not exposed and hence was not in contact with the skin. Now that it's exposed, it picks up moisture a bit less, allowing the jacket to breath even more.
Hood
If I'm going to be active with the hood, there's no way I'm putting on a Proton Lw over an Atom SL. Atom SL offers a StormHood. When the hood is in use, Proton Lw's standard hood falls behind. I'd pick Atom SL over Proton every day.
Weather resistance
They're very comparable. But I feel like the Proton Lw stands against the wind better.
Both are DWR coated.
DWR is a coating.
It's basically sprayed on to the surface of these jackets as a finish.
It stands for Durable Water Repellent - which means that water will be repelled under wet conditions instead of soaking into the fabric.
DWR also decreases dry time.
It's a good thing these jackets are coated in DWR.
But pay attention to the fact that DWR is a coating - meaning that it will wear off over time.
Which is why you might want to invest in a DWR spray such as this one at arcteryx.com for after treatment.
As you see, there's a strong correlation between FP x FW and temperature ratings, but not more than, say, 80%. I explained why this happens here in this post of mine.
Pockets
In addition to the hand warmers that take place in both jackets, the Proton Lw offers an additional external zippered chest pocket. The colored section you see on the chest make up the exact borders of this pocket. It's pretty large.
This adds to the weight a bit.
But an additional external pocket isn't the only advantage you get with Proton Lw in this regard. Its hand warmer pockets are also larger than those of the Atom SL.
- Proton Lw hand warmer pockets dimensions: 10.26 inches (or 26 cm) height x 7.1 inches (18 cm) width
- Atom SL hand warmer pockets dimensions: 6.1 inches (or 15.5 cm) height x 8.1 inches (or 20.5 cm) width
In other words, each hand warmer pocket of Proton Lw is around 50% larger (73 in^2 vs 49 in^2).
Weight
Both jackets are super light (12 vs 9.5 oz), but Atom SL is lighter.
Packability
I don't understand why Arc'teryx doesn't make a stuff sack for these. Their down jackets always get one.
Patagonia always offers a stuff sack for Nano Puff and Micro Puff. They're kind of their Atom and Proton (light synthetic jackets).
Not packing the Hw or even the base models can be understandable. But superlight models? Not so much. I'm pretty mad about this.
Sleeves and cuffs
Sleeve lengths are the same at 25.6 inches (or 65 cm) for size M.
Fit
Proton Lw comes with a revised fit. Atom SL offers legacy fit.
I'm 5'11", 165 lbs, athletic build. Size M fits me perfectly.
My size is always the same. Arc'teryx, Patagonia, TNF, Salomon, Columbia, Nike, Adidas, Under Armour, Zara... Doesn't matter.
Historical versions of Proton Lw
The previous Proton Lw, e.g Proton FL, was a bit different than the new model. The hood wasn't insulated, and the insulation throughout the garment was not exposed. Instead, it was the mesh in contact with the skin. Previous model also offered an extra external zippered chest pocket and came with legacy fit, obviously.
Arc'teryx Atoms vs Protons: Best colors
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Poll results: Best colorways of Atom Series
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Poll results: Best colorways of Proton Series
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Craig G says
What do you think of the updated Fall 2019 Proton LT compared to the updated Fall 2019 Patagonia Nano Air? I think this would be a great comparison!
Canberk Koksal says
Craig,
Most important thing to note here is that these 2 jackets are MUCH more alike than they’re not. I’d say they’re 90% the same (except the Air looks quite ugly and Proton LT looks quite gorgeous to most people).
The scores in this chart might help you:
https://outdoorcrunch.com/synthetic-insulated-jackets/
As you see, Nano Air is a perfect technical piece. Proton LT, on the other hand, is also a perfect technical piece, but, compared to Air, it’s also more suitable for casual outgoings as well.
If you’ll be using the jacket both in the town when it’s cold out AND during high output activities, I’d recommend Proton LT.
If you’ll be using it during high output activities only, I’d recommend the Air.
Hope this helps.
Neonomide says
Great comparison! Some notes though. I think that the new Proton has a new internal liner as well, no? If Permeair is new, then basically they changed every material in the jacket! Seems a pretty big overhaul for me. I always felt that the old Proton had a too thick outer fabric, and it could pack a bit better and breathes less than Nano Air. Preferred the Proton fit all the way. Atom LT did not do it for me (those annoying side panels).
Arc’teryx developed a lighter Proton FL at the same time with Octaloft insulation and the lighter Fortius 20 outer fabric (which it now shares with new Proton LT. I’d have to check out the new LT out if I didn’t have the old one. For now, I’ll be getting the FL for layering and maximizing the breathability.
In the meanwhile, I’d love to see Proton LT old vs new comparisons!
Rob S says
Just discovered Arcteryx a couple years ago, and I’m glad I did. Nothing else provides the technical details involved it making super light but warm outdoor gear in my opinion. Just curious as to how the Atom AR was rated as providing more warmth than the Cerium Lt? I have the Cerium Lt and sweat with it indoors at room temp. I know the Atom AR has slightly more synthetic insulation,, but figured as far as strictly warmth, down is warmer overall, no? If that’s the case I’m going to seriously look into an Atom AR for the future as I do prefer synthetic over down,,, mainly because with down you can never wear anything black or dark colored without feathers attaching to your sweaters etc. Great detailed review. Thank you.
Janusz Martinsson says
Hi!
I live in Sweden and have both jackets.
You forgot to mention one important thing in difference.
The Atom LT can stand against in fairly windy conditions while the Proton LT has absolutely no wind barrier at all and you have to put on a shell. The wind blows right through the Proton.
Canberk says
Thank you for sharing your thoughts and experiences Janusz 🙂
Thomas says
Hi,
The Atom LT has been updated with the same Coreloft Compact as Proton LT this year, so with 20g less but same insulation materials, isn’t the Atom LT being less warmer but more air-permeabe in 2020?
Thanks
Ross m says
Where does the Gamma LT Jacket fit into this?
Thanks for the great review!
Canberk says
Hi Ross,
Gamma LT isn’t insulated. Check out my guide to Arc’teryx Shells if you’re interested in more information about the Gamma LT.
Giuseppe says
Hello,
love your reviews, I would like to know your opinion about the Proton LT and the Atom AR.
Which one do you recommend to wear for a daily base stand alone jacket (I live in London, so basically deal with the UK weather)
Thanks
Canberk says
Thank you for your comment Giuseppe!
Atom AR is warmth focused, and the Proton LT is breathability focused. Correct me if I’m wrong, but London must be freezing now haha. So, unless you’re planning to use this jacket for high output activities, I’d get the Atom AR. Perfect for stationary use. Plus: Synthetic insulated structure of the Atom AR doesn’t keeps warm even under damp weather (unlike down insulated jackets). An important point for London, if you ask me.
Matt says
Anyone else noticed a size difference between Proton and Atom?
I have historically always been a small in everything Arc’teryx but not as of late.
Small in Nuclei, Proton and also the Kyanite (I know it’s a fleece but nonetheless) is dreadfully tight and I have had to go up to a medium. Small still fits perfect in both 2020 Atom iterations though. Go figure…
Tze says
Hi –
It seems the Atom LT has been updated with Coreloft Compact 60gm. Have you tested this version as it would seem that this should improve the breath ability?
Thanks
olivier says
Hey thanks for the reviews it really helps! I live in Montreal, Canada and I’m shopping layers to put underneath my Beta AR. I have a very good first layer, a couple of fleeces and obviously a Beta AR. So from what I understood, when I go resort skiing, the Atome LT and Proton LT would both be good options? I’m used to having one ski jacket and this layer system is diffirent for me. Thanks for your help!