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Reviews > Clothing > Jackets and Vests > MontBell Frost Line Parka > Test Report by Richard Lyon

MontBell Frost Line Parka
Test Series by Richard Lyon

Initial Report October 16, 2011
Field Report December 31, 2011
Long Term Report March 1, 2012


Male, 65 years old
Height: 6' 4" (1.91 m)
Weight: 210 lb (95 kg)
Chest 46 in (117 cm), sleeve 36.5 in (93 cm), waist 37 in (94 cm), torso 22.5 in (57 cm)
Email address: montana DOT angler AT gmail DOT com
Home: Bozeman, Montana USA

I've been backpacking for almost half a century, and regularly in the Rockies since 1986.  I do a weeklong trip every summer, and often take three-day trips.  I'm usually camping in alpine terrain, at altitudes 5000 to 13000 ft (1500 - 4000 m).  I prefer base camp backpacking, a long hike in with day trips from camp.  Though always looking for ways to reduce weight, I'm not yet a lightweight hiker and I usually choose a bit of extra weight over foregoing camp conveniences I've come to expect.  Winter adventures are often on touring or telemark skis.

INITIAL REPORT – October 16, 2011


MB ParkaThe Frost Line Parka is a new insulating layer from MontBell that features a removable hood and box construction to maximize the warmth from its 800-fill goose down.  

Manufacturer: MontBell Co. Ltd.,
Listed dimensions, size M: Center back length, 30.3 in (77 cm); compressed size 8.3 x 8.9 in (21 x 23 cm)
Listed weight, size M: 24.3 oz (689 g). That size has listed 6.7 oz (190 g) of fill weight.
Measured dimensions, size XXL: Center back length: 34.5 in (88 cm) (measured from the bottom of the collar to the hem), sleeve length 37.5 in (95 cm); compressed size 9 x 14 in (22.9 x 35.6 cm), measured in the stuff sack included with the Parka.  That’s still a bit puffy; I’m certain I could get it smaller in a compression sack.  In the photo at right the Frost Line in its stuff sack is seen next to a stowed four-man tarp tent.MB Parka stuffed
Measured weight, size XXL: 31.5 oz (893 g). Of this the hood weighs 3.9 oz (111 g).  
Materials: 800-fill power goose down, 30-denier Ballistic rip-stop nylon shell, 30-denier Ballistic nylon taffeta lining, 100-wash rated POLKATEXョ DWR treatment
Size: XXL (Available in unisex XS/ S/ M/ L/ XL/ XXL)
Color: Black is the only shell color available in the XXL size.  Other sizes are available in indigo, terracotta, and burnt umber (brown?).  The taffeta lining is grey.
MSRP: $235 US
Warranty: Lifetime warranty to the original owner against defects in workmanship and materials.  Repair or replacement requires the customer to ship the product to MontBell at the customer’s expense.


Features.  Two things differentiate the Frost Line from other down jackets from MontBell that I’ve worn.  (Test Reports on two such pieces may be found elsewhere on The more obvious is the Frost Line’s panoply of features.  This is not a minimalist insulating piece stripped of anything that might be sacrificed to save weight or pack space, rather it is feature-rich and appears constructed for seriously cold-weather use:

  • The long cut includes extra length in back, so that the hem comes about eight inches (20 cm) below my waist, covering about half my oversize gluteous maximus.  This makes the Frost Line suitable as an outer layer.
  • I can’t quantify it, and it may not be an apples-to-apples comparison as my other MontBell down jackets were not available in XXL, but the Frost Line feels more generously cut in the shoulders and chest, reinforcing its maker’s claim of outer layer use.
  • MB Parka inside pktThe Frost Line has five generously sized pockets.  The outside handwarmer pockets are lined with micro-fleece and are soft and cozy.  Inside the jacket are two drop-in pockets, each large enough for a one-liter water bottle or climbing skins, even the super-fat skins shown in the photo. These may be secured at the top with hook-and-loop closures.  A smaller zippered mesh pocket, also visible in the photo, is large enough for my wallet and mobile phone, with some room left over. 
  • The Frost Line’s collar measures four inches (10 cm) at the zipper ends and three inches (7.5 cm) at the center of the back.  When the jacket is zipped up this might be considered a built-in neck gaiter.
  • The hood (called a “tunnel hood” by MontBell) is massive, certainly large enough to fit comfortably over my ski helmet.  And it’s easily attached or removed by means of a zipper and snaps at each corner.  The hood fits inside one of the drop-in pockets with ample room to spare.
  • The sleeves are long, and may be cinched at the cuff with an “adjustable” (MontBell’s word) hook-and-loop closure.  When attached these cinch just beyond my wrists – a first for me in anything not custom-sized.
  • Finally, there’s a draw cord for waist adjustment.  The toggles are at the inside corners of the hem, and MontBell cleverly placed the means of adjustment -- the ends of the cord – inside the handwarmer pockets so that I can tweak the adjustment with bare but protected hands.
Construction.  The second difference is the Frost Line’s method of construction.  Typically down sweaters have compartments (baffles) for down that are “sewn through” – separated by seams sewn through the two outer fabrics.  Box baffling, a means of construction regularly found in sleeping bags, separates the baffles with gossamer fabric that extends between the shells, keeping the loft more uniform. This is the feature most prominently touted by MontBell, and the one that prompted my application to test the Frost Line.  I can personally attest to the increased warmth that elimination of seam lines generates in down insulating garments from other manufacturers, and this will be a focus of my testing.

Appearance.  As with every MontBell product I’ve owned, I found no flaws in stitching, zippers, or anything else.  The outer fabric isn’t shiny or crinkly, and the taffeta lining is quite comfortable.  This Parka looks and feels ready for winter.

FIELD REPORT - December 31, 2011

Winter’s refusal to visit North Texas and a limited travel schedule have kept me from exposing the Frost Line to seriously cold weather.  In less demanding conditions though the Parka has performed admirably.


The weather did accommodate this test as best it could on a two-night, three-day backpack in the Texas Hill Country, as nighttime temperatures fell to 25 F (-4 C), the only days this fall and winter the mercury dipped below freezing.  I wore the Frost Line in camp and added it atop my customary merino base layer and sweater in my sleep system.  I’m trying out a quilt for winter use, so at this temperature some additional covering is required for my head and torso.  Camp wear of the Frost Line was usually under a rain shell, as all three days had frequent showers and squalls.  

I also took the Frost Line on an overnighter in a state park near Forth Worth, Texas, in similar though slightly warmer conditions.  Again the Parka warmed me in camp and in my quilt.  The rain stopped late at night, so the rain shell wasn’t needed at breakfast.

I have frequently worn the Frost Line at home on daily early morning and pre-bedtime walks with my dog.  Whenever the temperature was below 40 F (4 C) I would don the Parka instead of a lighter jacket, over everyday street clothes.  I packed the Parka on my Christmastime trip to visit my sister and her family in Wilmington, Delaware, but the weather didn’t oblige – the only cold day (about 35 F/2 C) featured driving rain.


Size.  I’m normally right on the diving line between XL and XXL when purchasing upper body clothing, and based upon MontBell's sizing chart that was true here.  XXL was better for body and sleeve length, XL for the chest.  I opted for the larger size because I plan to use the the Parka as a winter outer layer, to ensure that it would fit comfortably over several layers and that it wouldn’t ride up in the back.  I’m glad I did so, even though the Parka’s more generous cut makes it drape somewhat loosely in the torso when worn only over a couple of cotton shirts (on the dog walks) or even a couple of merino layers (on the backpacks).  I can cinch the waist, cuffs, and hood to keep the wind out.  Also the extra sleeve length is much appreciated.  I should point out to any of you considering a purchase that the Parka’s sizing differs from what I’ve encountered with other MontBell products.  Base layers and midlayers, though in my opinion true to size, have a trim fit.  The Frost Line is roomier, as I think a top layer should be.  I like the cocoon effect.

When moving my ski gear from the attic to the house I took a minute to try the tunnel hood’s fit over my helmet.  As with the body, the fit is a bit loose (despite my size XL helmet).  Use in windy conditions confirmed this, as I’ve often had to cinch the hood when walking into the wind if I’m to keep the hood atop my head.

Insulation.  This is a warm jacket.  Its best test has been in my sleep system, where I’ve stayed toasty warm with a quilt rated at 15 F (-10 C).  With a quilt the upper body insulation is on its own on my torso and head, and I didn’t notice any difference where the quilt stopped and the Frost Line took over.  [Often I do – I am a very cold sleeper who usually packs a bag rated 10-15 F (6-9 C) degrees colder than the expected temperature.]   

The Parka’s box baffling has been noticeable in windy conditions, particularly on dog walks.  I have not felt a draft at the seams, as I certainly have when wearing a sewn-through down sweater (also from MontBell).  

Durability.   The Frost Line looks as good as new after its limited duty in the past two months.  More importantly, not a single feather has escaped.  I’ve had no need to clean the Parka.  As noted above, when there was real rain I added a rain shell, but on several dog walks I wore the Parka on the outside through ground fog, mist, and drizzle, and any drops beaded right up without visible effect on the down.


Comfortable fit
Really warm


The Frost Line is somewhat bulky when compressed in its stuff sack.  I’ve had better results with a compression sack, so I wish that one had been supplied with the Parka.

LONG TERM REPORT - March 1, 2012

Now that I've worn the Frost Line in really cold weather I'm increasing my already-high marks for this versatile parka.


Overnight use was limited to a three-day, two-night hike in Montana in late January.  It was scheduled as a hut-to-hut ski trip, but there simply wasn't enough snow to ski the planned route (or to get my mandatory downhill skiing in), so we converted it to a combination hike and snowshoe camping trip.  This was in the Absaroka Range, maximum altitude about 7000 feet (2100 m), in clear weather and unseasonably warm temperatures, up to 50 F (10 C) during the day and down to only 15 F (-10 C) one night.  I wore the Frost Line at rest stops, and once we reached camp in the evenings, over a base layer and almost always a sweater as well.  In the tent I combined it with a merino beanie,  merino base layers,  and a hybrid quilt rated to 15 F (-10 C). 

I also wore the Frost Line at breaks on two dayhikes in Montana, in similarly unseasonable weather - daytime highs again near 50 F (10 C) and clear weather.  These were short trips, two to four hours each. On these hikes I wore only a long-sleeved merino tee shirt while hiking, so the parka went on anytime anyone wanted to stop.

The really cold weather referred to above was on a three-day business trip to Geneva, Switzerland, which was suffering its coldest winter weather in a decade - daytime highs no more than -10 C (15 F), and on a ski day sponsored by my hosts in nearby Megeve, France, as low as -15 C (7 F).   And it was  much colder at night, with a City low recorded as -21 C (-3 F).  Geneva sits on a lake, and it's always windy, making for some truly frigid conditions.  I wore the Frost Line over a business suit at the meetings and over two merino layers on the slopes. 


Insulation.  It keeps me warm.  Really warm.  The parka's performance in Geneva was superlative, in conditions that in one sense were more demanding than backpacking.  When planning for exercise in cold weather I'm able to vary or add layers to keep my trunk warm.  Not so when dressed in a suit for a business meeting.  The  Frost Line did its job  more or less by itself, as the thin wool of a suit jacket, with its open front, didn't add much.  Thank goodness for goose down.

I have enjoyed the warmth provided by the parka in my sleeping quilt as well.  Over merino base layers and a sweater I've stayed warm without resorting to the dreaded mummy hood.  Because I can cinch up and snap the hood the insulation moves with me when I toss and turn, so I don't wake up with my face buried in fabric, setting off a claustrophobic reaction.

The parka's insulating ability means I can't wear it  when hiking, even in cold, blustery conditions.  On my hikes I keep it strapped to the front of my pack, to be donned the minute we've stopped for a rest or a photo opportunity, and I pop it on once we reach our destination.  Even though I sweat some inside it when performing camp or cabin chores such as splitting wood I want to avoid a chill.

Durability.  I have yet to notice a feather escape, and the outer fabric has withstood minor brushes with trees and shrubs without a mishap.  I can't recall a sticky zipper or other malfunction.  I haven't tried shifting the down to a particular location, such as the front when wearing the  Frost Line in my sleeping bag, and it hasn't happened accidentally from hanging the parka on a hanger, scrunching the down when sleeping,  or cramming it among the compression straps on my pack.   I'd say the Frost Line is functionally as good as new. 

Features. The Frost Line's most noteworthy feature is its box baffling, which serves its purpose well.  Even on exposed locations when hiking, or in Geneva, I didn't feel any drafts at the seams.  In my unscientific opinion this means of construction adds more than a few degrees to the parka's insulating ability.  (As an aside, box baffling is a considerably more intricate, and therefore expensive, manufacturing process than the sewn-through construction more commonly found on down garments.  For those of my readers who may balk at the Frost Line's price, I offer one unqualified vote that it's well worth it.)

Another feature I really like is the soft liner inside the handwarmer pockets and at the neck. These add both warmth and prevent the discomfort of chafing in cold dry weather. 

This parka's other design features do their jobs too.  After some practice I've managed to operate the toggles on the back of the hood and at the hem, and the hook-and-loop closures at the cuffs, with one gloved hand.  Adding pulls on all the zippers is a very useful touch, again allowing easy and snag-free one-handed operation.  Cinching the hood closed at night keeps the drafts out and, as noted, staves off the panic attacks. 

Frost Line in MontanaWHAT I LIKE

Overall the Frost Line is an exemplar of the KISS (Keep it simple, stupid!) principle.  Everything that's included has a purpose, and accomplishes that purpose simply and well, without unnecessary frills.  Using box baffling for a parka is especially praiseworthy.


At this point, nothing. I have compression sacks that I can use to get the Frost Line down to manageable size for packing. And a bit of extra bulk is a small price to pay for the warmth provided by this parka.


I've just moved to Montana, where the Parka has already begun to get daily use even in this mild winter.  It's still well below freezing on the early morning and pre-bedtime dog walks! Here I am in the Frost Line on the deck of my new home, looking forward to new adventures in the snow. 

My Test Report ends here, with a big “thank you” to MontBell and for this testing opportunity.

Read more gear reviews by Richard Lyon

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