Sleeping Bag Buying Guide

What is a Sleeping Bag?

A sleeping bag is essentially a protective blanket that closes on 3 sides most commonly found with a zipper or other fastening device. Sleeping bags are an alternative to a bed in activities such as hiking or camping. Sleeping bags are composed of insulation materials layered in padding, and then enclosed in a durable shell to protect the user from natural elements.

How does a sleeping bag work? Sleeping bags keep you warm by trapping and holding a layer of "dead" (non-circulating) air next to your body. This air, which is warmed by your body heat, forms a barrier between you and colder air or cold surfaces

Sleeping Bag Diagram - SnugPak 91080 Softie 3 Merlin, Olive

• Hood - The quilted top of the bag is tailored, pleated, and fitted with a draw string so it pulls into shape, much like a hood on a jacket.
• Neck Baffle - All SnugPak double layer bags have this baffle to minimise heat loss.
• Anti-snag Zipper - To prevent the 2-way zip from snagging either the zip baffle or the bag edges, an "anti-snag strip" of webbing is sewn in behind the zip. (All zipped bags.)
• Liner Fastening and Hanging Tabs - Inner tabs are provided to keep a loose liner in position, corresponding in position with the tabs we provide on our liners. External tabs allow you to easily hang the bag for airing and drying.
• Circle Foot - Tapering the bag to a circle foot creates the "mummy" shape which is easy to warm and minimises the weight of material used.
• Zip Baffle - Hard to see in the picture, but a zip baffle runs the full length of the bag, behind the zip,to prevent heat escaping through the zip area.

Selecting a Sleeping Bag

When selecting a sleeping bag there are several items to consider. There are two major distinctions with sleeping bags: standard sized sleeping bags, and mummy bags. Their unique shapes offer distinct advantages for specific uses. When purchasing a sleeping bag for traditional camping use, a standard moderate or light weight sleeping bag will provide ample warmth. Standard sleeping bags usually are not as warm as light weight mummy bags. If you plan to go on backpacking trips or sleep in extreme climates, consider selecting a mummy bag. Mummy style bags insulate more effectively and are your best choice for colder, higher elevation conditions. Rectangular bags give you more room to change sleeping positions but offer more space around your body that must be heated up.


Sleeping Bag Types and Styles
Standard Sleeping Bag - A standard sleeping bag is traditionally rectangular in shape, and comes in varying lengths to accommodate a person height. These sleeping bags are great for stationary or light camping, but do not serve well in more extreme climate situations. Since these bags are rectangular in shape, they can be rolled easily for storage, but are not very compact and can be rather bulky.

Mummy Sleeping Bag - Mummy bags are a more slender bag that tapers at the feet. They get their name from the “mummy shape” that resembles a mummy’s coffin. Mummy bags also typically feature head protection from a hood that closes up tight to keep in warmth. Mummy bags are exceptionally lightweight, and can easily be stuffed into very small bags or sacks. Mummy bags insulate more effectively and are your best choice for extreme climate condition.


Sleeping Bag Materials
Sleeping bags are made from lightweight insulation materials such as down, cotton, wool or several other synthetic materials. Down is the wispy, fluffy undercoating found just beneath the outer feathers of geese and ducks. This natural fiber is an extraordinary insulator. Goose down is preferred to down from ducks, because it is believed it offers a higher "fillpower."Down fill is the most expensive choice for insulating materials as it weighs the least and retains heat the best. If a down sleeping bag gets wet, it should not be used until dry, as it will be ineffective at keeping a person warm and can lead to hypothermia. Cotton and wool make for inexpensive choices for sleeping bags, but do not fair well when wet, are much heavier, and are only suggested for stationary camping. Several types of synthetic materials exist on the market that are light in weight and have good heat retention. Synthetic fill does not easily absorb water, and even if wet, can still keep a person warm. Synthetic materials are for the most part plastic threads, extruded polymers. These threads are most commonly a continuous filament. They can also be arranged in short "staples" up to four inches long. Usually the threads are hollow, reducing their weight and enabling them to trap more air. Synthetic materials also do not usually last as long as down. Down will usually outlast synthetic by many years.


Sleeping Bag Features
Temperature ratings - Sleeping bags are rated for their effectiveness at keeping a person warm in different temperatures. Sleeping bags are rated by their lowest possible effective temperature. When choosing a bag for a particular climate or season, it is recommended that you purchase a bag that is 10 degrees lower than your intended temperature use. For example, if you plan to camp in 40 degree weather, choose a bag rated for 30 degrees weather. Bags are usually grouped into 3 classes: Cold Weather for temperatures 10 degrees and below, Multi-Season for temperatures from 15-32 degrees, and Warm Weather for temperatures 35 degrees and up. The ability to retain heat in a sleeping bag also relies on proper care and storage, and if they are being used in conjunction with a sleeping mat or pad. Temperature ratings should be used as a general guide when selecting bags in cold and moderate climates. The effectiveness of a sleeping bag and its temperature rating can vary by manufacturer. Also consider your body’s own inclination to become warm or cold.

Hood - Up to 25% of your body temperature can escape through your head. Selecting a sleeping bag with a hood that can close around the head and face can help ensure no heat is lost. Hoods have a draw string to cinch around the face, and sometimes a Velcro flap to securely fasten the area around the neck.

Draft tube - A piece of material that runs the length of the zipper to prevent cold air from seeping in through the zipper.

Weight - Sleeping bags can come in varying weights, so choose wisely if you plan to do trips where carrying a light weight bag would be an advantage. Sleeping bags composed of down are going to be much lighter than the synthetic alternative. The lightest weight sleeping bags weigh around 2-4 pounds. Heavier bags, typically made of synthetic fibers, generally weigh 5 pounds or more.

Length and Width - Sleeping bags come in many lengths and widths. It is critical that you select a bag that will fit you properly. A bag that is too long, too short, or too wide will not keep you as warm. Some manufacturers make men, women, and children specific bags with different shoulder and hip widths.

Sleeping Pads - comfort is an important factor when using a sleeping bag. It is strongly recommended that a sleeping pad or mat is used in conjunction with a sleeping bag. Sleeping pads help add much needed cushioning to hard surfaces, and they can also help insulate the sleeping bag from lower ground temperatures. Sleeping pads come in a variety of sizes and shapes. Some pads are foam mats that roll up, and other advanced mats inflate to hold air as a cushion.

Many factors affect your ability to keep warm inside a sleeping bag

• The insulating pad beneath your bag. When sleeping on frosty ground at high elevation, you need a full-length pad to keep you separated from the cold. When sleeping on snow or frozen ground, two pads are recommended.
• The presence or absence of a tent. A tent or bivy shelter traps an extra layer of dead air, warming it up to 10 degrees more.
• Your metabolism. You might be a cold sleeper, and want more insulation or a warm sleeper, and want less insulation.
• Your gender. Women frequently prefer bags with lower temperature ratings since they tend to sleep colder than men.
• Clothing worn while inside the bag. Dry long underwear and clean socks are good choices on cold nights. A cap and neck gaiter keeps body heat from radiating away. Fleece pants and jackets help on colder-than-expected evenings.
• Adjustments you make while in the bag. Keeping the bag zipped up and the hood cinched on cold nights will help retain the most heat. Be careful to not breathe into the bag, since the trapped moisture has a negative effect on the insulation.
• Food in your stomach. The process of digestion helps produce warmth.
• Hydration. If you're not well hydrated the food won't help much.

Even experienced campers and backpackers can be surprised by unexpectedly cold conditions, particularly during trips in the spring and fall. It's benificial to be prepared.