Sleeping Bags

REI Thermo Pod -20 Sleeping bag You’ve chosen your backpack and are now looking for a sleeping bag.   Don’t hurry through this decision.  A sleeping bag can make or break your trip, so take your time to choose wisely.  As you will find, there are basically two types of insulation used as fill in backpacking sleeping bags.  Goose and duck down is the most comfortable and lightest fill, but even down has its problems.  The synthetic materials, such as Primaloft and Quallofil, are your other choice.  Synthetics have come a long way in the last two decades, making it a feasible choice for backpacking.  Each type of fill has its pros and cons, just like everything else, and no one sleeping bag will be good for every situation.  So think carefully about the types of trips you plan to take and buy accordingly.  The outline below lists some of the features you should look for, as well as some tips on caring for your bag.

Down is much lighter and more compressible than the synthetic materials.   It has a greater warmth-to-weight ratio than synthetics.  This means you can get a lighter weight bag and it will keep you as warm as a synthetic bag that weighs considerably more.  It can also be compacted into a smaller space, which is very important when you have an internal frame backpack and the bag is carried on the inside.   Down bags are much more expensive initially than synthetic bags, but since they last as much as four times longer, they are cheaper in the long run.  The main problem with down is that it is useless when wet.  Loft, or trapped warm air, is what actually keeps you warm, not the weight of the fill.  Down is very absorbent, causing it to mat down when it gets wet.  It also takes a long time to dry.  It is useless as insulation once it gets wet; therefore, you must always use some kind of shelter to protect the bag.  Even in dry conditions, your body produces some moisture and on trips you should air the bag daily to dry it out.  Down also requires special care when it comes to cleaning.  Follow the manufacturer’s cleaning instructions carefully.  If you take your bag to dry cleaners, be sure that they specialize in cleaning down.  I had a friend who had a North Face Blue Kazoo down sleeping bag, which he brought to a cleaners who had said they knew how to clean down.  From the time he got it back, it never lofted very well again.  Because of his experience, I don’t trust the cleaners and will launder them myself.  To launder your bag, be sure to use down soap, usually available at the store where you purchased your bag.   Laundering your sleeping bag is a time-consuming process.  Always wash your bag in a front-loading machine.  The agitator motion in most washing machines can easily rip the baffles inside of your sleeping bag.  The baffles are pieces of material that stabilize the down and keep it from settling.   It will take several hours to fully dry your bag.  It’s a good idea to put a tennis shoe in with it to help break up the clumps of down so it can dry faster and more effectively.
Synthetics are made from polyester; the same material used in the leisure suits of the seventies!  It is very easy to care for but doesn’t breathe as well as the natural fibers.  Because of this, synthetic bags can feel clammy and are not as comfortable over a large range of temperatures like down bags are.  But they definitely have their place in many backpacks.  Different conditions call for different strategies.  Synthetic bags are perfect for wet conditions—conditions that you would encounter during a canoe or sea-kayak trip or in really wet weather.   Synthetic materials don’t absorb water and mat down; therefore they hold their loft and ability to retain heat even when wet.  Once synthetic bags do get wet, they dry quickly.  They are very easy to care for—just throw them into a front-loader machine, then the dryer for one cycle.  Use a mild soap rather than a detergent.

No matter which sleeping bag you choose, it is important to store it loosely in a large cotton bag.  Never keep it packed in its stuff sack after your trip.   Before storing my bag, I like to put it through one dryer cycle to thoroughly dry it out.

Some of the important features to look for in a wilderness-worthy sleeping bag are:

A sleeping bag that fits your body, both in its width and length.  A mummy-shaped bag is the best choice for backpacking.  The reason for this is because a mummy is made to fit the contours of your body without a lot of wasted weight.  Not only does it help reduce the weight of the sleeping bag, it also makes the bag more efficient for your body to heat, minimizing the cold spots.  Don’t go too far in the other direction and get a bag that is too small and uncomfortable.
A two-way zipper with a draft tube to prevent cold air from coming through the zipper.  This allows unzipping from either end to provide better ventilation.
An insulated hood that is shaped and can be pulled around your head with a draw cord, preventing heat loss through your head.  It is also very helpful to have a draft collar at the base of the hood so you can tighten the bag around your shoulders without having to tighten the hood.
Good insulation in a shaped foot box.  Some manufacturers also have a durable nylon lining in the foot box so you can put stove fuel or other items that need to be kept warm inside with you.

Updated:  07/28/00