Western Mountaineering MityLite Sleeping Bag: Ideal Choice for Summer Backpacking

mitylite sleeping bag in nature camping

When packing for your backpacking trip, one of the most important items you will pack will be your sleeping bag. Unlike car-camping where you do not have to worry about the weight of your sleeping bag or how much space it takes up, the reverse is true for backpackers.

For any backpacker, weight and volume are among the first and biggest concerns when selecting camping gear. Fortunately, manufacturers have found a solution to this dilemma by making lightweight and very compressible gear that fits in backpacks just fine and adds minimal weight.

An example of such compressible and lightweight gear is the Western Mountaineering Mitylite Sleeping Bag. The key among the things that make your backpacking experience an amazing one is how you spend your nights. That is why backpackers always pay special attention to the type of sleeping bag they use.

However, before you worry about how comfortable your nights should be, you have to focus on how you get your gear there. Backpackers are always looking to minimize the weight of their gear and companies like Western Mountaineering are rising to the challenge.

MityLite Sleeping Bag is a member of the ExtremeLite sleeping bag series from Western Mountaineering, which are designed to make your backpacking trail less cumbersome and your night more enjoyable.

Just like the rest of the sleeping bags in the ExtremeLite series, the MityLite sleeping bag lives up to its name by staying very light and compact when not in use and then turning into a comfortable cradle once you reach the campsite.

The sleeping bag comes with various features that make it just right for lightweight summer backpacking. Its features of premium quality are underpinned by the highly-rated Down insulation.

We know that Down is superior to the low-quality synthetic and the traditional sleeping bags. Having the MityLite sleeping bag will not be a regret to the avid camper. Read through the important aspects that it has to offer below.



The MityLite Sleeping bag comes in a package with the stuff sack included which compresses to 6 x 12 inches. The product is Moss Green in color and has a size of 6ft 3in. It has an insulation of a 12 oz Down Fill. It further comes with what you need to have and that includes the extra features such as the storage pockets.

mitylight sleeping bag full size

If you need other accessories such as the sleeping pad, you will have to purchase them and tuck them into the sleeping bag effortlessly. Be reminded that this sleeping bag has no hood. This is, nonetheless, not a big deal or a deal-breaker to the quality of this bag. One can have the pillowcase.

To create more space for two people, it can be zipped to the Western Mountaineering Summer Coupler. So you must get this too. You might also have to purchase the sleeping pad to compensate for the rough terrains.

Design & Durability

The fabric finishing is designed to retain its water repelling properties for as long as possible. It is finished with an excellent water repellant designed to stay 80% intact after 20 washings. This may, however, depend on the method of washing and general handling.

Should you feel that your bag is becoming less repellant to water, you can re-treat it and take it back to its initial effectiveness. This sleeping bag is quite versatile in usage. Its semi-rectangular shape and full-length zipper allow you to choose how to use it depending on your camping situation.

It makes an amazing sleeping bag for one, but it can also be changed into a cozy sleeping nest for two by opening it up and zipping it onto Western Mountaineering’s Summer Coupler. Additionally, if you wish, you can turn it into a comforter by opening the zipper all the way and spreading it out quilt-style.

mitylite sleeping bag on floor

Even though it is lightweight, it is designed in such a way that it prevents leakage and maintains excellent performance. The sleeping bag has waterproof fabric with a tight weaving and the highest threat count.

To minimize weight and volume, however, Western Mountaineering had to compromise a bit on fabric strength so the bag should be handled with care to avoid damage. Because the sleeping bag is hoodless, it can easily be adjusted to fit your preferred sleeping side in relation to zipper side.

Whether you sleep on the right side or the left and whichever side you want your zipper to be, it can all be achieved by simply flipping the bag onto the other size because there is no hood to get in the way. The sleeping bag comes with a full-length YKK #5 double pull zipper and to keep the zipper opening and closing without any flaws, stiffening tape is lined along the zipper line.

A firm locking head further enhances the performance of the coil zipper. The internal baffles are made with pre-cut no-see-um netting material which prevents them from getting distorted while at the same time remaining flexible so they can compress when it is time to pack up. This material further ensures that the bag is both lightweight and durable.


The use of insulating material is not to create warmth for you, but rather to minimize loss of the warmth created by your body. The more body warmth your bag can trap inside, the warmer you will stay. For insulation material, Western Mountaineering uses high fill power goose down, which provides excellent warmth to weight ratio.

Man in a sleeping bag looking at the landscape

The use of down makes the sleeping back amazing in proving warmth while keeping it much lighter than it would have been, had it contained synthetic insulation material. Down has, for so many years, been a reliable insulation material for many outdoor sleeping bags.

Temperature Rating

The MityLite Sleeping Bag is your ideal choice for summer backpacking. At 40° F of temperature rating, the sleeping bag is designed for summer camping with options to adjust the warmth to give you your ideal night in the summer outdoors.

In case it gets too hot and you feel like reducing the warmth a bit, the continuous baffle construction allows you to push the down under you and if you need more warmth, just shift more down onto the upper side.


The biggest limiting factor when backpacking is weight. Almost every gear-related decision a backpacker makes is guided by how much weight that particular item is adding to their gear. This holds true especially for main items like sleeping bags which can be quite bulky.

Fortunately, manufacturers have devised means of making lightweight sleeping bags. However, to achieve the ideal backpacking weight, they had to compromise on other features like material and durability.

mityLite sleeping bag folded

To achieve the lowest possible weight, the makers of sleeping bags had to play around with materials and shape to ensure that some of the features given up in an attempt to lower weight are somehow redeemed.

At just 1 lb 10 oz of total weight, the MityLite sleeping bag lives up to its name by adding very little weight to your camping gear load. It comes with a compression sack that squeezes it down so you can fit it in your backpack. Its lightweight and compressible properties make it ideal gear for lightweight backpacking.

A key consideration when designing a sleeping bag will be the season. This cuts across all other design features and is the main determinant in how the final product looks like. Winter backpacking bags, although still lightweight, are more likely to be heavier than those used in warm weather are.


Having been filled with 850+ FP Down, it is proof that this sleeping bag is waterproof. The exterior shell is made of water repellent properties that repel water in the wilderness. The ripstop shell fabric has properties of water resistance on the outer lining.

Down itself has the waterproof membrane. So, even if water penetrates the fading water resistant coating, down insulation will have the power to shield the interior with its waterproof qualities. Although Down is waterproof, if, mistakenly, it gets wet, it can take time to dry. Waterproof qualities will not have much of the effect in this regard.

Sleeping bag drying on the clothesline

Whenever using the sleeping bag directly onto the ground, please use a waterproof cloth to make a protective layer between your sleeping bag and the ground. This ensures that it is protected from dirt and any other debris that might be on the ground.

Secondly, it is better to put a layer between your body and the sleeping bag to protect the inside of the bag. This can be achieved by using a sleeping bag liner or wearing some covering clothes before entering the bag.


The shape of your sleeping bag is not a mere decorative feature.  Mummy shaped sleeping bags, for example, are ideal if you are looking for a bag with more warmth and less weight. However, because of their narrowing shape, they restrict body movement and might not be very comfortable.

Wider sleeping bags are more comfortable but they are also bulkier and retain less warmth. Car-camping sleeping bags may be rectangular-shaped, have more room and are bulkier while semi- rectangular ones are made for the backpackers.

bulky sleeping bags

Two compatible bags of this shape can be zipped together into a cozy sleeping space for two. This sleeping bag is semi-rectangular and is large enough to accommodate two people sleeping in it. The sleeping bag comes in only one size of 6’3″ so it will not accommodate anyone taller than that.

There are no Summer sleeping bags longer than 6’6″ from this brand that have the same properties as MityLite so anyone taller than this would have to look to another brand for a sleeping bag of similar features. If you are shorter than 6’6″ however, you have your pick of summer sleeping bags from Western Mountaineering.

Unique Features

Every product is sought-after with its unique features, and it is the same with this sleeping bag. The first unique feature we spot is the sewn-thru construction that adds an indispensable value in its insulation capabilities when coupled with the Down Fill Power of 850+.

On top of that, the bag comes with a semi-rectangular shape that can be turned into a lightweight comforter. The full-length #5 YKK zipper will help you improve insulation whenever sleeping in the bag. And for couples, the bag can be zipped to the Summer Coupler for them to sleep comfortably.

ykk zipper on mitylite bag

It saves them cost of purchasing yet another sleeping bag. Perhaps the other unique feature is the hoodless design that still functions well, regardless. The downside is that your head is not having a preferential warmth supply. Hoods can also be used as pillowcases.

This sleeping is, nevertheless, still functioning conveniently in the absence of the hood. This absence can be offset by wearing a warm cap or by purchasing a warm pillowcase.

Value for money & guarantee

Spending on a sleeping bag as an enthusiastic outdoor activist has never been a waste of time, especially when you spend on a product of high quality. All you have to take into account is the premium quality of the sleeping bag and the guarantee that it will certainly last you long.

The Western Mountaineering comes with a lifetime limited warranty should you notice any defects prematurely. The company reassures you that you bought a quality product. In terms of value, you will be spending around $400 to own this sleeping. Add to this, of course the shipping costs if any, to your respective region.

sleeping bags in nature

The other costs, although optional, are the sleeping pads or the pillows. But the bag is thick enough to be used on its own. Unless you plan to use it on a rough terrain, then you should probably consider purchasing a sleeping pad.

Additional Tips from the Manufacturer

The MityLite sleeping bag is easy to care for and does require specialized maintenance. However, it is made from delicate materials and should be handled with care if you want it to last.


To clean the bag, simply wash it in a bathtub. If you prefer to use a washing machine, then you must use a front loading machine. The baffle construction of the sleeping bag can easily get damaged if you use an agitator machine or a top loading one.

washing sleeping bag in bathtub

Do not attempt to dry clean the bag as the solvents used do not go well with the oils in the down. When hand washing, leave the bag in its stuff sack and submerge it in water that has down soap in it.  Leaving the sleeping bag in its sack keeps the air out of the baffles, making the washing process easier.

Restoring water repellency

If your sleeping bag starts to lose water repellency, you can re-treat the fabric of the outer shell to restore the repellency. For this, Western Mountaineering recommends using ReviveX Spray On Water Repellent.

Down Leakage maintenance

To keep the outer shell of the sleeping bag, breathable, it is made with a porous fabric. This means that down and feathers might escape through the pores in the fabric. This is not a defect and should not alarm you. To fix this, simply reach in and pull that cluster of down back into its chamber.

Western Mountaineering MityLite 40 F Sleeping Bag has it all that you are looking for in a sleeping bag. It is a perfect companion for summer hikes or backpacks with this temperature rating. The bag is compact and lightweight and has, among others, a sewn-thru construction and a semi-rectangular shape.

These are unique features that give it identity. For minimalist backpacking, it can be zipped to the Summer Coupler to create an ample space for couples to sleep together, without the need to have an additional sleeping bag. The insulation of this bag is on par with the 850+ Fill Power Down.

mitylite sleeping gear

Down has got plenty of benefits. Among others, it is highly compressible and offers an unrivaled comfort and loft. Moreover, it has a great warmth-to-weight ratio, which means that you will get warm with a lightweight sleeping bag.

It retains most of your body heat. Furthermore, this sleeping bag is waterproof because of the Down’s waterproof membrane. It is also durable and retains its original loft for many years to come.


  • Versatile functionality
  • Excellent warmth-to-weight ratio
  • Easy to clean
  • Very light
  • Very compressible


  • Only one size
  • It has no hood to specifically cover your head
  • It takes longer to dry should the Down get wet
  • Not for all-season-round camping

Ultimately, there are three main considerations to focus on when buying a backpacking sleeping bag and these are weight, insulation and temperature rating. Everything else, in one way or the other, feeds into these three so these should be given special focus as the ultimate drivers for your decision.

In order to give you more options, we have provided the similar and the competitor models for you, and have elaborated on their advantages and disadvantages compared to the MityLite sleeping bag. It turns out that MityLite remains competitive with its features and does not differ widely with the high-end sleeping bags.

We will be happy to hear your thoughts

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