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MontBell Plasma 1000 Down Jacket Review

Although certainly a very dependable jacket, the Plasma seems to be more of a technology statement rather than a high-value jacket.


Overall Rating: Recommended

The Plasma attains benchmarks: 1000 fill-power down, stitching that maximizes loft while keeping the down in place, and the lightest down jacket currently available – for which we give it our Recommended rating. However, in spite of all this, when you do the research, there are comparable jackets available at lower cost, including Montbell’s own Ex Light Jacket. Is the Plasma 1000 mostly a technology statement?

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by Will Rietveld |


As the name suggests, the Plasma Jacket features 1000 fill-power down, which raises the bar for a premium down insulated jacket. But that’s not all; this Spartan jacket also features MontBell’s 7 denier (25 g/m2) shell fabric, for a garment weight of 4.8 oz (136 g). For comparison, a midweight wool baselayer weighs about 8 oz (227 g).

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Fill-power is the volume in cubic inches that one ounce of down will expand to fill (left image). Just a few years ago, 800 fill-power down was considered top shelf, now we are seeing more garments and sleeping bags insulated with 900 fill-power down, and the Plasma 1000 Jacket (right image) is the first garment to utilize 1000 fill-power down.

Furthermore, the Plasma 1000 a good value at US $269 compared to other ultralight high-end down sweaters. So, what’s not to like? It seems to tower above everything else. Well, it’s a bit of a conundrum, as explained below.


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The MontBell Plasma 1000 Down Jacket, introduced in fall 2013, is insulated with 1000 fill-power down quilted in a 7-denier (25 g/m2) ripstop nylon shell. The only notable features are a full-height #3 zipper, standup collar, and simple elastic cuffs. It does not have any pockets or hem drawcord. MSRP is US $269.

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The Plasma 1000 has a unique sewn-through quilting pattern (left image) designed to promote down loft while keeping stitching to a minimum. Held up to a strong light (right image), the jacket’s uniform down distribution is apparent.

So far, MontBell has not adopted water-resistant down for their down garments and sleeping bags. Since they use premium down in most of their insulated products, they want to make sure the treatment does not impair down lofting or longevity. Also note that the Plasma is currently only available in unisex sizes, whereas the Ex Light is available in both men’s and women’s versions.

So, What’s the Conundrum?

The main competition to the Plasma 1000 is MontBell’s own Ex Light Down Jacket, and when you analyze the numbers, the Ex Light is actually a better value and arguably a warmer jacket.

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Montbell Plasma 100 Down Jacket (left image) and Ex Light Down Jacket (right image).

The following table compares the two jackets; data are from the MontBell website and my own measurements.

Montbell Plasma 1000Montbell Ex Light
Shell7-denier7 denier
Down Fill-Power1000900
Fill Weight1.6 oz (45 g)1.8 oz(51 g)
Fill Weight x Fill-Power1600 in2 (26.2 L)1620 in2 (26.6 L)
Garment Weight (Mens M)4.8 oz (136 g)5.6 oz (159 g)
Measured Loft (double layer)1.25 in (3.2 cm)1.75 in (4.5 cm)
Center Back Length28.4 in (72 cm)26.6 in (68 cm)
MSRP US $269US $199
  • A key comparison is Fill Weight x Fill-Power, which is the Total InsulationVolume (TIV) in the jacket. The Ex Light has a bit more.
  • Loft was measured in the chest area just below the arm pits. (The loft of the Montbell Ex Light Jacket is based on a 2008 model I own.)
  • The difference in TIV shows up in the loft measurements; the Ex Light has 28% more loft.
  • The difference in garment weight is only 0.8 oz (23 g).
  • Although MontBell specifies a shorter back length for the Ex Light, I found it to be identical to the Plasma 1000 (based on my 2008 jacket).
  • Note that these inferences are from a comparison of one jacket of each model.

In summary, the Ex Light weighs only 0.8 oz (23 g) more than the Plasma 1000, but it has significantly more loft and costs US $70 less. The Plasma 1000 is an excellent cutting edge jacket, but it appears to make more of a technology statement rather than a functional difference. Bottom line, it’s very similar to the Ex Light Jacket.

Another consideration is the amount of down in the jackets expressed as a percent of garment weight. Down in both jackets accounts for only 32% and 33% of jacket weight; the rest is fabrics and a zipper. Adding a bit more down to either jacket would substantially increase performance with minimal weight increase.


 - 5
I tested the Plasma 1000 Jacket on 8 multi-day trips totaling 26 days, plus numerous cool weather day hikes. Testing included an early spring Alaska trip and numerous summer backpacking trips with camps above 12,000 ft (3658 m).

Sizing is listed as “trim”. I’m 6 ft tall and 170 lbs (1.83 m and 77 kg) and normally wear a size Large; I found the Plasma to be true to size. It has enough girth to wear over a fleece midlayer.

For me, the Plasma 1000 provided sufficient warmth for summertime mountain backpacking trips, and is a great piece to provide warmth with minimal weight for any active pursuit. It’s my insulation layer of choice for my Mountain SuperUltraLight 6 lb (2.72 kg) base weight gear kit. It’s also the right amount of insulation to extend the warmth of a 30 F (-1 C) sleeping bag, which I usually recommend for mountain backpacking, or more accurately to attain the bag’s claimed temperature rating. In Alaska’s Kenai Peninsula I managed to stay warm (barely) on a 22 F (-5.6 C) night wearing the Plasma and a shell jacket inside a 30 F sleeping bag.

The Plasma 1000 is a bit of a “lightweight” for camp temperatures below freezing. A shell layer over it traps more heat and substantially extends its warmth. For active pursuits the Plasma is very comfortable in temperatures well below freezing.

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The Plasma 1000’s shell has a good DWR treatment that makes water droplets bead up (left image). However, in my puddle test (right image), where I place 1 fl oz (29.6 ml) of water on the jacket for 1 hour, most of the water soaked through the stitching and collected on a tray underneath. The Ex Light Jacket had similar results when I tested it several years ago.


Data in the following table are manufacturer specifications for men’s size Medium. There are many ultralight down jackets on the market, but these are the closest comparisons.

JacketFill-PowerGarment Weight (oz)Cost (US$)
Montbell Plasma 100010004.8 (136 g)269
Montbell Ex Light9005.6 (159 g)199
Mountain Hardwear Ghost Whisperer Down Jacket8507.0 (198 g)300
Patagonia Down Shirt8005.9 (167 g)249
Crux Pico Top9706.0 (170 g)299
GoLite Selkirk Ultralite Jacket8006.0 (170 g)140
  • The MontBell Plasma 1000 and Ex Light are the standouts for light weight.
  • The Mountain Hardwear Jacket and Patagonia Down shirt are overpriced.
  • The Crux Pico Top is seriously lightweight, but expensive.
  • The GoLite Selkirk has zippered hand pockets and a hem drawcord, so it’s hard to believe it weighs just 6 oz (170 g). If the weight is accurate, this one is a steal at $140. The Total Insulation Volume is 2000, which is higher than the Montbell jackets.

Conclusions and Recommendations

A truly ultralight down jacket is a very versatile piece year-around, for summer backpacking and cold weather active wear. Bottom line, the Montbell Plasma 1000 and Ex Light are the lightweight standouts in this seriously ultralight jacket category; both are exceptionally lightweight. However, the GoLite Selkirk is the wild card in the table above; if the weight is accurate, this jacket weighs only 1.2 oz (34 g) more than the Plasma and costs half as much. That’s hard to overlook.

My recommendation would be to double the amount of down in the Plasma Jacket, which would differentiate it from the Ex Light (and others) and substantially raise the warmth to weight ratio in a sub-7 oz (198 g) jacket.


"MontBell Plasma 1000 Down Jacket Review," by Will Rietveld. (ISSN 1537-0364)., 2013-11-05 00:00:00-07.


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MontBell Plasma 1000 Down Jacket Review
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Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: 1000 fill on 11/09/2013 13:50:53 MST Print View

I think the 1000 fill thing is more oneupmanship and on the edge of practicality. It has been noted that less lofty fills that have some feathers in the mix may hold their loft better than the uber puffy stuff. Some mentioned wearing a shell over the jacket reviewed and my first thought was how the loft would hold up. The insulation layer is already so thin that any compression is significant. I think you need some "reserve" loft to get any real efficiency if used with a rain shell. IMHO, you need 2" or so loft to get a garment with enough warmth to be practical.

At 2+" loft the weight difference between an 800 fill jacket and a 1000 fill version are really quite small. I assume an 800 fill jacket would cost less and would have a longer service life and work better in a layered system. Even a 700 fill jacket wouldn't be that much heavier: the fabric used in the shells as well as the cut and feature set have as much influence in weight and loft.

The other thing to consider with thin "belay" insulation is that is is only good for a narrow band of temperatures. Will noted that the jacket is weak for belay use below freezing. A fleece with base layers and wind shell would be effective above freezing. I reach for puffy layers when it is colder ( and drier) and then I want something with some real loft.

Adam Kilpatrick
(oysters) - MLife

Locale: South Australia
Re: Re: MontBell Plasma 1000 Down Jacket Review on 11/10/2013 17:51:37 MST Print View

At the risk of starting a flame war, I very much agree with Dale on this.

Especially if you are anything above average in metabolism when awake, there's not much point in having a double windshirt with a smidge of fragile down in between. In fact, its more like two windshirts perforated with a lot of stitching, leaking heat.

I guess it really depends on what conditions you are in, but unless its a really dry trip, I'd struggle to choose this myself. Certainly, the Plasma with extra stitching and arguably more fragile down is less of a good choice. Spring/Autumn in arid conditions would be great, if your camp behavior means you are up and out of your sleeping bag still after dark (more likely if you aren't solo). Otherwise you'd be much better off just carrying a single windshirt, and putting the weight saved into extra down in your quilt or sleeping bag.

Also, the Ex Light might also be slightly warmer as it might have less stitching overall. At the temperature ranges these jackets are useful, the two layers of 7 denier might provide just about as much warmth as the 40g of down if they weren't perforated.

Anthony Huhn
(anthonyjhuhn) - F - MLife

Locale: Mid West
Patagonia Love on 11/10/2013 20:45:40 MST Print View

I was just nitpicking the statement that the montbell is the first jacket to use 1000 fill power, I know, I'm a jerk for even mentioning it. But I think the whole pataguchi secret process that turns 800 fill into 1000 fill water-resistant down is cool. Any one want to let me cut open their $700 jacket to see if I can figure out how they do it?


Confused Newbie

Locale: Northern CO
Re: down and wet weather on 11/12/2013 11:50:36 MST Print View

Thanks all for the advice on the down. If I am not digressing too much from the topic of the discussion...what do you all prefer to store your down in for sleeping? For cold wet weather, say 35F and rainy, do you bring a fleece with for hiking? I can't help but recall the "cotton kills" statements I heard about insulating properties of wet cotton while younger; seems like down is similar, but the advantages of dry down are too good to pass up.

Stephen M
(stephenm) - MLife

Locale: Mind your own business
Re: Re: down and wet weather on 11/12/2013 12:07:14 MST Print View

Any clothing items I am not using while sleeping go in to a dry bag (the same one they are stored in during the day).

Ian B.

Locale: PNW
Re: Re: down and wet weather on 11/12/2013 12:25:23 MST Print View

Due to the PNW often living up to its wet reputation, I was slow to convert to down. Seeing that my bargain 550 fill down sweater is 14oz, Costco down vest is in neighborhood of 6-8oz, and my fleece vest is >14oz (sorry for vague numbers/going from memory), I found down to be worth the risk.

My down sweater or vest and sleeping bag stay in a dry bag when I'm hiking. I only bust out the sweater or vest to stay warm during breaks as I rarely need more than a shell and base layer for anything above 20* as long as I'm moving. I wouldn't hike while wearing down due to perspiration issues as you mentioned. If I'm looking at sub-20* temperatures where it's likely that I'll hike with extra insulation on, I'd bring synthetic insulation in lieu of down. I'm a fan of the military style polypro for this purpose but I have a fleece vest too.

Justin Baker
(justin_baker) - F

Locale: Santa Rosa, CA
Re: Re: down and wet weather on 11/12/2013 12:27:04 MST Print View

"cold wet weather, say 35F and rainy, do you bring a fleece with for hiking?"
I definitely bring a fleece in that weather or even a wool sweater. After stopping in the evening and setting up camp I take it off and put on a dry down jacket.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: down and wet weather on 11/12/2013 13:14:24 MST Print View

Down to even 20 F, I just wear nylon base layer and eVent jacket (and fleece hat, fingerless fleece mittens,...). Definitely have to walk briskly. Carrying a pack uphill I'll stay warm no problem.

When I stop I'll put on synthetic or down vest depending on the temperature.

Confused Newbie

Locale: Northern CO
Re: Re: Re: Re: down and wet weather on 11/13/2013 17:41:48 MST Print View

Thanks. Sounds like down vests, etc. are primarily in-camp gear, and I am reasonable to bring a fleece as a hiking layer.

Justin Baker
(justin_baker) - F

Locale: Santa Rosa, CA
Re: Re: Re: Re: Re: down and wet weather on 11/14/2013 20:19:58 MST Print View

If for anything, a fleece makes a good layer for stops and breaks in wet weather. When you are wet you cool off much quicker at rest and a fleece won't be affected much at all from putting over damp clothes. Down would get quite damp. Personally I like a fleece vest, very easy to slide on and off.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: fleece and wet weather on 11/15/2013 02:05:24 MST Print View

"If for anything, a fleece makes a good layer for stops and breaks in wet weather. When you are wet you cool off much quicker at rest and a fleece won't be affected much at all from putting over damp clothes"

Good fleece will actually move your perspiration right on out away from your skin and base layer. Fleece also allows the option of wearing it without a shell for those times when it isn't windy but you want just a bit more warmth. It's really hard to wear down without a shell unless you are a goose :)

Vests deserve more attention. It would make a good article, comparing weight/volume/warmth of a vest vs a jacket and there are many product lines that offer both, so it could be a real apples and apples comparison. I often carry a light fleece vest for summer day hike backup insulation where the nighttime temps don't get so terribly low.

Alok Karnik
(doogan) - MLife
(Fill weight*fill power)/ shell weight on 11/06/2014 10:16:59 MST Print View

Another good measure to determine the overall usability of the jacket would be (fill weight * fill power)/ (total weight - fill weight) Lets call this term "shell efficacy"

[The denominator is effectively shell weight + zips etc]

this would be a good mesurement of efficacy of a agreement. For example, a super high fill power low weight garment with very little fill, as alluded to in this article, is not as effective as a slightly heavier garment with much more fill, because, in simplified terms, the garment is not fully utilizing the jackets shell material. This measure is just quantifying this statement. Lets take an extreme example. A jacket with a shell material with 2000 fill power with a shell that weighs half as much as the next shell material on the market would still not be as "effective", using this measure, if it has anything less than 1/4th the fill of the next lightest jacket, even if its absolute weight is lower.

You could even take this a step further and take "shell efficacy"/absolute weight to determine shell efficacy across different weight classes of garments.

I am fairly sure all my math is right, but i'm doing this off the top of my head, so please call me out if my math is wrong.


Edited by doogan on 11/06/2014 10:21:24 MST.