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).
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.
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.
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.
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 1000||Montbell Ex Light|
|Fill Weight||1.6 oz (45 g)||1.8 oz(51 g)|
|Fill Weight x Fill-Power||1600 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 Length||28.4 in (72 cm)||26.6 in (68 cm)|
|MSRP||US $269||US $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.
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.
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.
|Jacket||Fill-Power||Garment Weight (oz)||Cost (US$)|
|Montbell Plasma 1000||1000||4.8 (136 g)||269|
|Montbell Ex Light||900||5.6 (159 g)||199|
|Mountain Hardwear Ghost Whisperer Down Jacket||850||7.0 (198 g)||300|
|Patagonia Down Shirt||800||5.9 (167 g)||249|
|Crux Pico Top||970||6.0 (170 g)||299|
|GoLite Selkirk Ultralite Jacket||800||6.0 (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.