Air permeable warmth.
Noticing that most "breathable" insulated jackets don't actually breathe that well during fast-paced activity, Arc'teryx designed the Women's Proton LT Hooded Insulated Jacket for high-octane alpine missions where thermoregulation is key to completing your lofty objectives. Instead of being merely breathable, the Proton LT is air permeable, meaning it allows rapid air exchange without relying on built-up pressure to expel condensed perspiration along the inside of the shell. Ultimately, this means you'll stay pleasantly dry from the inside-out, especially on those hard climbing objectives and long slogs en route to the summit.
The Proton LT is a great piece for cool transitional seasons, courtesy of its Coreloft Continuous insulation. This synthetic insulation won't succumb to soaking-wet conditions, meaning it won't clump together when wet and lose its lofting ability like down. The shell's DWR treatment beads off passing showers and snow, keeping you dry through light precipitation. For greater weather protection, layer it underneath your waterproof hardshell as a toasty mid-layer for backcountry skiing and alpine objectives in severe weather. Other key features for sealing out the elements include an adjustable hem, stretch-knit cuffs, storm flaps under the main zipper, and helmet-compatible hood with adjustable drawcords.
- Softshell jacket for fast-paced alpine activities
- Fortius Air shell provides air permeable protection
- Coreloft Continuous insulation provides mid-weight warmth
- DWR treatment sheds oncoming showers and light snow
- Insulated, helmet-compatible hood with drawstring adjustment
- Flaps underneath main zip for sealing out blustery conditions
- Adjustable hem with dual drawstring adjustment
- Zippered hand and chest pockets
- Item #ARC00JU
- Q & A
Great All-around Mid Layer
- Familiarity: I've used it several times
- Fit: True to size
- Size Bought: Medium
If you are like me, you might be looking at this jacket and wondering what difference between this piece and the Atom LT jacket is, so from my experience thus far, here are a few items of note that might be helpful for comparison:
- The Proton is more breathable, but I think the Atom might be a bit warmer. The breathability will be the biggest differentiating factor for this piece.
- While the fits are supposedly the same or very similar, I prefer the Proton as the cut feels slightly longer and a little more tapered/feminine.
The best way I can think of to describe the fabric of the Proton is that it is slightly more "porous" than that of the Atom. I canât yet comment on the difference between the water resistant abilities but the Atom is better at blocking the wind.
I also personally appreciate the extra pocket on the chest (which the Atom doesnât have).
I took the new Proton LT as the sole jacket on my recent trip to the Dolomites. It was much colder there than expected and found this jacket to be a great all-around piece, but because it is so breathable found it slightly less wind resistant. We did a hike to the North faces of Tre Cime di Lavaredo and saw varying conditions from light snow, to wind, and various elevation changes. Aside from wishing I had a hardshell for the more extreme wind and cold, it did a great job of regulating my temperature (particularly once I starting exerting myself) - I will be excited to see how it does this winter for SkiMo.
As far as sizing is concerned, as with most all Arc'teryx articles, I sized up to a Medium.