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Reviews > Clothing > Jackets and Vests > MontBell Plasma 1000 Down Jacket > Test Report by Richard Lyon

MontBell Plasma 1000 Down Jacket
 Test Series by Richard Lyon

Initial Review November 27, 2013
Field Report January 31, 2014
Long Term Report March 28, 2014


Male, 67 years old
Height: 6' 4" (1.93 m)
Weight: 200 lb (89 kg)
Chest 46 in (117 cm), waist 37 in (95 cm), torso 22.5 in (57 cm), sleeve 36.5 in (93 cm)
Email address: Montana DOT angler AT gmail DOT com
Home: Bozeman, Montana USA

I've been backpacking for nearly half a century, most often in the Rockies.  I do at least one weeklong trip every summer, and often take three-day trips.  I'm usually camping in alpine terrain, at altitudes 5000 to 10000 ft (1500 - 3000 m).  I prefer base camp backpacking, a long hike in with day trips from camp.  Recently I've been actively reducing my pack weight, though I still tend to include my favorite camp conveniences.  I always sleep in a floored tent and like hot meals. Winter adventures are often on telemark, touring, or randondče skis.

INITIAL REPORT - November 27, 2013


The Plasma 1000 is MontBell's latest down jacket designed as a midlayer - for use over a base layer but not intended as the user's sole upper body insulation in colder temperatures. MontBell was a pioneer in the manufacture of down midlayers as a lighter weight, more compressible alternative to fleece or wool. Reviews of several of its earlier products in this genre are available elsewhere on I have been fortunate enough to have reviewed two - the U.L. Down Parka and the EX Light Down Jacket. MontBell states that the Plasma 1000 is the "next level" up from the EX Light. (Or maybe it's the next level down, as the upgrade is reduced weight.) Like its model the EX Light the Plasma 1000 is a low-frills sweater - the only features are a two-inch (5 cm) collar and elastic at the sleeve cuffs, and the latter is not very substantial. No pockets, no drawstring waist, no hood. The Plasma 1000 is about ultralight.

Plasma 3As can be seen in the photograph of the stitching at left, the Plasma 1000 has sewn-through construction - each down chamber is completely sewn up. Instead of the more common rectangular chambers, however, the body and sleeves of this garment have sewing halfway up or down from each horizontal seam, making a longer panel, from one vertical seam (the top and bottom of each sleeve, and from each sleeve seam to the hem of the jacket. In the catalogue that accompanied my jacket MontBell states that the sewing pattern is used "to promote down loft while keeping the thread used during stitching," to - surprise, surprise - reduce weight. Each sleeve has a raglan cut, with the seam's panels running about two inches (5 cm) down from the top of the sleeve rather than across the top. That's a nice touch to reduce abrasion and an uncomfortable pressure when the jacket is worn under a pack. 

Manufacturer: MontBell Co., Ltd.,
Listed weight, size M: 4.8 oz [136 g]
Measured weight, size XL: 5.75 oz [163 g]
Listed fill weight: 1.6 oz [45 g]
Listed center back length, size M: 28.4 in [72 cm]
Measured center back length, size XL: 29.5 in [75 cm]
Measured sleeve length, size XL: 34.75 in [88 cm]
Available sizes: S, M, L, XL, XXL At this writing the Small is listed as sold out. The Plasma 1000 is listed as a unisex garment.
Color: Dark Mallard [I'd call it teal. But then I could never tell one duck from another.] Also available in Off-White or Black; the XXL is available only in Black.
Materials: 7-denier Ballistic Airlight rip-stop nylon shell, 1000 fill power goose down
Includes: A small stuff sack that measures 6 x 8 in [15 x 20 cm] and weighs one-eighth of an ounce [4 g]
Warranty: Lifetime to the original owner for defects in workmanship or materials. A U.S. owner must send the product at the owner's expense to MontBell in Boulder, Colorado. May be subject to a mandatory cleaning charge.
MSRP: $269 US


Wow, it's light! It's no secret how MontBell dropped the listed weight of the EX Light, itself a garment streamlined for ultralight, by almost fifteen per cent, as the two have the same cut and the same fabric. The stitching pattern is one way to cut weight, as noted above. The other is the insulation. While the Plasma 1000 has less listed down fill by weight, what's included here is 1000 fill power goose down, something I didn't know existed. Fill power is determined by measuring the volume in cubic inches that one ounce of compressed down displaces. The higher the fill power the denser the down; the denser the down the better the insulation. Let's use the best available down, pare the necessary amount, and save some weight without sacrificing insulating ability. Anyway that's the theory. Testing will tell if this proves out in the Montana winter.

This jacket passed its first inspection without a demerit, as I have come to expect with products from this fine company. No loose threads, no protruding down, not a stitch out of place - in short, impeccable workmanship.

Plasma 2 As with the other down sweaters from MontBell that I have owned, size XL fits me quite well. True to its UL theme the Plasma 1000 has a trim fit that I prefer in a midlayer. I could use a small bit more length in the sleeves, but that's an issue I have with almost all athletic-fit garments thanks to my extra-extra long arms. That shouldn't present much of a problem when I'm wearing the Plasma 1000 under a parka, and I can cover exposed wrists with gauntlet gloves when the Plasma 1000 is my outer layer.

I wore the Plasma 1000 on a walk with my dog yesterday afternoon, atop a wool sweater but with no outer layer over it. In the windless sunshine the Plasma 1000 kept me nice and warm at a temperature (25 F / -4 C) at which I usually need more than a midlayer. The 1000 fill power down works great out of the box.


I only have one. My problems with the durability of the EX Light (see Test Report) and MontBell's warning on its website, in its catalogue, and on a hangtag (in solid capital letters, no less) that "DUE TO THE USE OF ULTRA LIGHT FABRICS, THESE GARMENTS MAY REQUIRE SPECIAL CARE" highlight my reservation about the Plasma 1000. How will the gossamer fabric hold up to use on skis and in the backcountry?

FIELD REPORT - January 31, 2014

After two months I am pleased to report very favorable results on the MontBell Plasma 1000 Down Jacket. Read on for details.


Backpacking: Five days, three nights. An overnight trip in a Forest Service cabin in the Gallatin National Forest, Montana, in early December, amid snow flurries with daytime temperatures in the 20s F (-4 to - 7 C) and a nighttime low of 8 F (-14 C). I did the hike on skis, about five miles (8 km) each way, with a pack weight of approximately 35 pounds (16 kg) including food and water. Then a three-day, two-night trek, also on skis, in Yellowstone National Park, Wyoming, December 30-January 1, also using a cabin. Similar pack weight, clear conditions except for a snowstorm one night, and temperatures from -5 to 25 F (-20 to -4 C). Both hikes at an elevation of about 6500 feet (2000 m). The only stiff elevation gain while hiking with a full pack was on the latter trip, about 700 vertical feet (200 m) in the first half mile (1 km), though after reaching the cabin we did  quite a bit of exploring with a lighter load.

Resort skiing: About fifteen days at either Bridger Bowl or Big Sky, Montana, and two days in Utah after the Outdoor Retailer show. Some clear days, some overcast days, some snow squalls, and some wind. The most extreme conditions while skiing (or anywhere else for me when wearing the Plasma) were at Bridger in early December, -20 F (-29 C), snow and blowing snow, and very windy. At Alta, Utah was the other extreme, 40 F (4 C) at times and no wind at all.
While resort skiing I normally wear a small daypack with water, a snack, avalanche beacon and probe (required for some Bridger terrain), and an extra layer.

Day trips: About a dozen, all but one on touring skis, in the Bridger, Bangtail, or Gallatin Mountains
near my home. Tours ranged from 1-8 hours, from generally flat terrain on the Fawn Pass Trail in Yellowstone National Park to the sometimes-daunting up-and-down trails at Bohart Ranch in the Bridgers, from -12 F (-24 C) to 25 F (-4 C), and from clear and sunny to whiteout snow squalls. My daypack is somewhat larger than my resort pack, maybe 30 liters (1800 cu in), with room for the resort kit plus lunch, a vacuum bottle with a hot drink, and a layer or two that I might remove during heavy exertion.

Home use: Almost daily for dog walks, shoveling snow, splitting wood, or other miscellaneous outdoor chores. Temperature range from -25 F (-32 C) to freezing.

Except around home I used the Plasma always as an insulating layer, atop at least one base layer and underneath a shell or parka. My general dressing rules for field activities were a merino wool base layer (almost always lightweight), Plasma, and outer layer. When resort skiing the outer layer was an insulated parka (Ground Terra, subject of an Owner Review on this site) or Windstopper-lined sweater (Dale Storetind, Owner Review in progress), and when it was really cold a second, midweight merino sweater under the Plasma. For day trips I sometimes substituted a softshell (Norrona lofoten, also reviewed here) for the insulated parka, and would carry a spare merino layer in my pack. On the two backpacks the spare was a heavier hooded down pullover that I donned at rest stops and used in my sleep system.

More for convenience than for any logical reason (it hangs next to the door), home use other than dog walks had the Plasma as an outer layer over my everyday clothes, usually a cotton or wool base layer and shirt or pullover sweater (or both).


Insulating ability. As a midlayer for outdoor activities the Plasma has helped keep me warm in some very cold weather. Though I am generally cold-prone my three-layer system has sufficed in all but the most miserable conditions, even when wearing only an uninsulated shell on top. I think the garment's athletic cut and (for me) nearly perfect fit have contributed to this. Remarkably the sleeves are actually a bit longer than those on my shell and parka, and the minimalist elastic at the cuffs keeps the cuffs at my wrists and keeps the snow out even after a fall. I've had no issue of the back of the jacket's bunching up and exposing my base layer (or worse) even when herringboning uphill on skis. The stand-up collar means standout performance in locking in body heat when I've zipped the Plasma all the way to the top; the collar is protective without being constrictive. In short, nothing at all to complain about on this score when used, as promoted by its maker, as a midlayer.

When used without a wind shield, though, the Plasma's weight-saving properties can compromise even its high density down's insulating abilities. When it's my outer layer, with even the slightest breeze I've felt a draft at the seams unless I had another insulating layer underneath. (As noted, I sometimes wore the Plasma over a sweater.) I intend this not as criticism; MontBell doesn't sell the Plasma as an all-purpose jacket or anything but a substitute for bulkier materials as a midlayer. Rather I note it as an observation that in fact bears out its advertised limitation.

Breathability and venting. The Plasma doesn't wick or breathe especially well. Several times after even moderate exertion (e.g., a bootpack at Bridger, a bump run in the sun at Alta, that initial slog up Slough Creek in Yellowstone) I have noticed a slightly damp sensation on my torso and perspiration along the Plasma's seams
, even at below-zero F (-17 C) temperatures. Perhaps this is an inevitable consequence of the athletic fit that traps heat so well, perhaps of MontBell's choice of the exceptionally lightweight fabric. More likely it's the lack of venting options on the Plasma. With no pit zips or pockets to open there's only one way to bleed off heat - opening the zipper at the collar. Again I'm observing, not complaining. I'm quite pleased to put up with the (very minor) inconvenience of unzipping my parka, unzipping the Plasma, and re-zipping the parka if necessary in return for the Plasma's superlative heat retention. Just another reminder that the Plasma is a niche product.

Tear Durability.  Heavy use over the past two months has dispelled completely my initial worries about the Plasma's ability to withstand the rigors of athletic use. Unlike its sibling the EX Light, which I also tested, there have been no problems with the zipper. I have only a single spot with a feather poking through, on the underside about four inches (10 cm) from the left cuff. (To the right of the quarter in the photo.) I didn't notice this at first and I'm willing to attribute it to my own carelessness when doing daily outdoor chores.

As for care, the perspiration reported above quickly evaporated without any stain visible to my eye. The Plasma has retained no odor. So I haven't had any need to wash it. It hasn't stretched or otherwise become misshapen and all stitching remains intact. But for that one little hole it looks as good and performs as well as new.  Very high marks in this category.


Several times I've identified the Plasma's limitations, to the point of calling it a niche product. I wish to repeat that I mean none of this as critical of the product or of MontBell. To the contrary, MontBell has in plain language disclosed to (even warned - see my Initial Report) prospective buyers what this jacket is and is not intended to do, which is all I ever ask of a manufacturer. And within its niche as a layering piece the Plasma's performance has been terrific.

LONG TERM REPORT - March 28, 2014

I haven't any breathtaking new observations to report. But continued almost-daily use of the Plasma has cemented my view that this is a top-flight layering piece. 
In summary, it's not exaggeration to say that I wore the Plasma on at least part of one hundred days during the full test period. And I've been very pleased (as well as warm).


Backpacking: Two more overnight trips to nearby Forest Service cabins and a two-night ski trip
in the Teton Range, Wyoming, in February. Because of avalanche danger both local trips were short, relatively level hikes of two and five miles (3 and 8 km), each with about a forty-pound (18 kg) pack. One weekend was very cold - down to maybe -20 F (-29 C) at night, -15 F (-24 C) just as we arrived at the cabin. By these standards the other trip was downright balmy, with a nighttime low only about 5 F (-15 C) and trekking temperatures as high as 20 F (-7 C).

In the Tetons I carried
a lighter pack weight, as an outfitter had stocked food and sleeping bags at the yurts. We experienced generally clear conditions at 5 to 25 F (-15 to -4 C), much closer to the higher temperature when trekking.

On these trips I wore the Plasma as a midlayer most of the time, over a merino base layer and under either a heavy wool sweater (see my Owner Review of the Dale of Norway Storetind on this site) or a windbreaker. On an especially difficult uphill I might shed the outer layer if it wasn't too windy.

Skiing. Many more days of resort skiing and cross-country touring in Montana, wearing the Plasma each time. Weather and temperatures were similar to those recounted in my Field Report, though without the brutal cold. (That was the weekend I skied to the Forest Service cabin.) Also a half-dozen or so day skis on local trails, at temperatures down to 5-10 F (-15 to -12 C), usually in the woods and so somewhat shielded from the wind. Again the Plasma was under a sweater or jacket and over a thin merino base layer.

Other. One ten-mile (16 km) day hike, mostly with cleats but a bit on snowshoes. Scattered snow showers, 10 F (-12 C), entirely in the trees. Here my outer layer was a lined parka.

Plasma in pack Most frequent use, however, was around home, on dog walks and during outdoor chores such as shoveling snow or splitting wood. These have been almost daily duties given the frequent snow and the fact that my house is heated by a wood-burning masonry stove. Temperatures have gone as low as -29 F (-34 C), though the worst outdoor conditions occurred in early March at -20 F (-29 C) and fierce winds - delightful temperatures for the dog but far too cold for me. If the chores were immediately before or after a local outing, I wore the outing gear. On other days, when the temperature exceeded 0 F (-18 C) during chores I wore the Plasma over a tee shirt; if lower I added a down jacket on top. When walking the dog I invariably added the down jacket.

It hasn't often warmed to the point of shedding the Plasma because I overheated, but a couple of times I did take it off on serious bootpacks. Rather than use the stuff sack supplied with the product I simply jammed the sweater into the top of my pack, where it took up hardly any room. It even fits easily into my skinny resort pack, pictured here with the Plasma and a shovel and probe inside. That bodes well for use in warmer weather as an auxiliary warm-up piece when fishing or day hiking.


Insulating ability. Still great! Probably the best evidence has been doing chores at about 0 F (-17 C), often over only a cotton tee shirt. When it wasn't windy I stayed warm when shoveling the
front steps and deck and splitting enough wood for a few days, tasks that collectively took up to a couple of hours. As reported earlier if the wind kicked up some of the sewn-through construction compromised the insulating ability through drafts at the seams. As long as I stayed active, though, I only recall a single instance when I fled inside for a windbreaker or a hot chocolate.

Winter athletic activities present a dilemma for me. I'm quite cold prone and really bundle up at rest stops, in camp, and around town. But when active at 20 F (-7 C) I can be comfortable in a tee shirt and the Plasma almost completely unzipped for ventilation, even in all but really gusty winds. That's the beauty of layers, as with a windshirt, sweater, or parka ready to hand I can traverse a windy ridge, skin up an open trail, or shovel snow with just the Plasma keeping me warm.

I wouldn't add pit zips to the Plasma.
I've found that I can vary its insulating properties sufficiently by its one means of adjustment - the zipper down the front - so that it's not necessary to take it off in the bright sun at higher temperatures.

Through this winter test period I've used a heavier upper body layer for extra insulation when in a sleeping bag or quilt, but I definitely plan to put the Plasma to work in that capacity in the coming seasons, as I'll not need an insulated headpiece.

Breathability and wicking. The only thing that's puzzled me through the past four months' use of the Plasma is the ready build-up of perspiration at and adjacent to the seams. I don't recall that this occurred during my testing of two related MontBell products, the EX Light Down Jacket and UL Down Parka; certainly I didn't find enough to report. The only material change between the EX Light and the Plasma is use of denser down, so perhaps that great stuff's insulating properties simply make me warmer. I won't speculate and I certainly won't complain, as I'd far rather be too warm than too cold. In any event the presence of the perspiration hasn't compromised performance in the slightest and I haven't noticed an odor or seen a stain. Nor has the accumulated perspiration given me a clammy or other chilling sensation.

Durability and Care. The small rip reported in my Field Report remains, and a feather pokes through every once in a while. On a careful inspection I've found two other pinprick-sized holes, one at a seam under the armpit and the other in the middle of the back, on the inside. The location of these insignificant spots tells me that they were caused by ordinary wear and tear, not contact with a foreign object or other owner misplay, as I suspect caused the hole on the sleeve. Any down loss hasn't impacted insulating ability. I believe that this is a normal consequence of the super-lightweight fabric used to keep this product in the SUL category.

I haven't washed the Plasma, though not from fear of damage. (See the manufacturer's warning quoted in my Initial Report.) I tend not to wash down products until a wash is really needed. It's a nuisance and air drying takes the product out of service for several days, something I didn't want to do with the Plasma this winter. As the snow melts and local trails turn muddy I'll hand wash the sweater with down-specific detergent and air-dry it flat. That the Plasma hasn't needed a cleaning after all my use speaks highly of its durability.


The obvious - Great insulation from a garment that weighs less than six ounces (170 g) and packs down to less than baseball-size.

It's turned out to be quite durable. Whatever fabric problems MontBell may have had when it launched the EX Light have clearly been fixed.

Versatile - In addition to advertised use as a midlayer, it's warm enough for outer layer use in the absence of wind. As noted above I plan additional uses in the spring and summer.


No pockets. I'd take the extra weight in return for handwarmer pockets and a smaller compartment somewhere for keys. That's because I'd like to use this jacket even more. As I don't carry a purse the lack of pockets severely limits front country wear.

Price. This isn't an inexpensive sweater, even by high-grade down standards. Moreover its MSRP is more than one-third higher than that of its predecessor the EX Light, all for a weight savings of eight-tenths of an ounce (23 g) or so. I leave it to the reader to judge the benefit of that bargain.

My Test Report ends here, with big thanks to MontBell and for the opportunity to test the Plasma 1000. It has been a godsend this winter.

Read more gear reviews by Richard Lyon

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