Reviewed in September, 2020

Among hardcore alpinists, you won’t find a brand with more street cred than Montbell. This Japan-based company makes gear for people who truly use it and doesn’t spend much effort on paid athletes or splashy marketing campaigns. But the proof is in the pudding: Montbell makes some of the best ultralight insulation on the market, and because it’s mostly direct-to-consumer, the costs are reasonable for what you get. Our favorite ultralight down jacket in their lineup is the Plasma 1000 Alpine Down Parka. With 1,000-fill-power down (no, that’s not a misprint) along with an ultra-thin 7-denier shell, it offers by far the best warmth-to-weight ratio on this list. It’s not the absolute lightest option out there, but it’s a well-balanced UL piece that weighs next to nothing.

from SWITCH BACK TRAVEL

Reviewed in August, 2020

■Warmth: 4.9

With temps in Utah’s Little Death Hollow hovering around freezing on a November trip, the Plasma 1000 kept us warm over a T-shirt and light fleece as we did camp chores. On ski tours in the Rockies, we paired it with a baselayer and midlayer for comfort into the single digits. While sitting around camp, we overheated in this puffy at around 55°F.

■Packability: 4.7

For a jacket with such a dialed feature set, the Plasma doesn’t take up much space. It leverages premium, 1000-fill down (it’s not hydrophobic, but still jacks the price up) to squish into an eggplant-size cylinder with its included stuffsack. This feat is all the more impressive given that it’s the warmest jacket in the test.

■Durability: 3.5

The 7-denier ripstop nylon is among the most delicate here, crinkly, and saw its share of dings over a season. While scrambling up boulders to get a photo of the night sky from Little Death Hollow, one sleeve suffered a small tear on a sharp corner; we experienced a few of these tiny snags over 5 months of testing, but they never spread and we patched them easily.

■Features: 4.7

A beefy, fully insulated hood (not helmet compatible) is adjustable on the sides and back. The Plasma 1000’s full zipper makes for easy on/off, and two zippered hand pockets keep your digits toasty and hold small items. A DWR treatment was welcome while we pushed through dewy brush, but it doesn’t hold up to more than a quick drizzle.

■Overall: 4.5

from BACKPACKER

Reviewed in June, 2020

The MontBell Plasma 1000 is one of our go-to jackets for ultralight backpacking due to its exceptional warmth-to-weight ratio. Stuffed with the absolute highest quality down available (1000 fill-power), the Plasma is the most efficient insulator we’ve ever worn. Though this jacket weighs about the same as some of the other ultralight jackets on our list, (the Mountain Hardwear Ghost Whisperer/2 and the REI 650 Down), it definitely feels warmer. The biggest downside to the Plasma in our eyes is its price, which will make it prohibitive for many. However, if you're a thru-hiker or dedicated backcountry traveler looking for top-of-the-line ultralight warmth for 3-season trips, the Plasma 1000 is well worth the investment.

from CleverHiker