The Montbell Thermawrap jacket is one of the most popular jackets among backpackers and for good reason. We will be taking a look at what makes this ultra-light jacket such a great piece of gear.

Montbell is a Japanese company that makes a full range of gear and clothing for the outdoor enthusiast. They have two different sets of sizing; one for the American market and another for the Japanese market. The American sizing is closer than the Japanese line to the traditional American fit; however, it is still a bit smaller than the typical fit seen from American companies. For this reason, it is best if you are able to physically try their garments on before choosing a size. If this is not possible you must take into consideration how you would like the particular piece to fit into your layering system. Just keep in mind that their sizes to run a bit small so you may have to size up one from what you normally wear, especially in the case of shell jackets.

The Thermawrap is meant to be an inner insulation layer that can take the place of a heavier and bulkier fleece jacket. It has a full zip with a draft flap to keep the zipper from allowing cold air in. The waist hem and also the wrists have elastic that do a good job of keeping drafts to a minimum. I did find that the length of the jacket is a little too short as it tends to ride up to my waist. If I were to purchase this jacket again I would size up one size just for the extra torso length. There are no other features besides the simple, yet effective, hand warmer pockets to keep the jacket weight as low as possible. My jacket in a size small weighed in at 8oz including the supplied stuff sack. This is consistent with the weight listed by Montbell.

The workmanship of the Thermawrap was very good. I could not find any loose threads and the insulation was evenly distributed. The shell and lining material is an extremely thin proprietary nylon which Montbell has developed. It is quite effective at stopping wind because of its very tight weave. It does shed very light moisture but is not meant to be worn as an outer layer in full on rain or very wet environments. It does, however, dry very quickly because of the very thin shell material and synthetic insulation. In a jacket of this weight using down instead of synthetic insulation wouldn't provide much of a weight savings thus I think synthetic is the best choice for an ultra-light jacket. With a 4.5" x 8.5" pack size the Thermawrap only requires a tiny corner in your pack.

Although this jacket is very thin and extremely light it is quite warm and makes a fantastic layering piece. I have worn it with just a t-shirt underneath in weather ranging from 45-65 degrees. Even if it is windy you don't need another layer because it does such a great job of blocking wind. In the winter I have used the Thermawrap as a mid layer between a wool base layer and a hooded synthetic jacket as the outer layer. With these three pieces I have sat comfortably in temperatures down to 10 degrees with a moderate wind. A thick fleece is what this jacket is meant to replace and it does a fantastic job. An equally warm fleece jacket would be twice as heavy and take up at least twice as much space in your pack without the wind protection of the Thermawrap. The only negative I can find in this jacket is the price, but for those who are serious about shedding some weight from their pack and gaining some functionality; the Thermawrap is about as good as it gets.

Source: http://www.associatedcontent.com/article/1381872/product_review_montbell...