It’s little wonder that we develop strong personal feelings for our sleeping bags: What other piece of backcountry gear are we as intimate with? Beyond comfort, the right bag provides the emotional sustenance we need on a chilly, windy wilderness night. Let’s face it: Camping can be either a dark night of the soul or an uplifting sensual experience — and the determining factor often boils down to our selection of a nylon cocoon.
The wrong choice invites either sweats or chills. The right choice is usually a three-season bag. Such a bag is both lighter and roomier than vacuum-packed-snug mountaineering bags that have a foot of loft, but cozier than a light summer bag. And despite its season-bridging warmth, a three-season bag is still reasonably light and very packable. When you crawl in and exhaustion transports you to sleep, it’ll be the result of an honest day’s work on the trail, not the strain of lugging a heavy sleep-sack.
Narrowing the field
Most three-season bags are rated to 20 to 30 degrees Fahrenheit, a range that allows you the greatest versatility. It isn’t too warm for most summer camping, particularly in the mountains, yet it’s toasty enough for fall and spring outings. A few of these bags will even accept liners that extend their cold-weather range by 10 to 20 degrees, making them capable of some winter duty. But remember that temperature ratings are only ranges, and the guidelines are set by the makers. The bag that keeps you warm depends on its shape, your metabolism, whether you’ve added to your calorie stores before hitting the sack, and the quality of your sleeping pad and shelter. As a rule of thumb, buy a bag rated five to ten degrees below the coldest temperatures you anticipate. If you sleep cold — meaning your inner furnace goes on the blink at night — go an additional five to ten degrees lower.
This year’s miracle fiber for sleeping bags is Polarguard 3D, a new insulation with a familiar name, made by the same company (Hoechst-Celanese) that brought us Polarguard and Polarguard HV. All you really need to know is that the hollow-fiber fill is softer and lighter than the earlier Polarguard species, yet apparently just as durable. The majority of synthetic bags reviewed use 3D. The other common material is Primaloft, the most expensive synthetic insulation. Much like down, it incorporates very fine fibers to retain warm air; but unlike down, it is the least compromised when wet.
Synthetics: inexpensive wet-weather workers. These man-made fills retain insulating ability when wet — plus they dry quickly — so if you’re a boater or just end up in the rain a lot, synthetic fibers may be your best bet. They’re easy to clean, resist rot and mildew, and won’t make anybody sneeze. Synthetics are cheaper, too — those reviewed here go for under $200, which is where three-season down bags start.
Down: less weight, more filling. Still, down remains my favorite insulation. It’s more compactible, more durable, and has a higher warmth-to-weight ratio. It also is more comfortable: Down drapes easily, thereby molding a bag to your shape, so a down bag feels more snug. And down fills keep getting better in terms of what’s called fill power. This figure indicates how much space an ounce of down can fill. An ounce of 550-fill down will expand to 550 cubic inches, 650-fill to 650 cubic inches and so on. Up until a year ago, 700-fill down was the Rolex of down. But now Marmot and Moonstone sell 800-fill down, while others regularly use 750- and 775-fill. The weight advantage may be slight, but loftier down comes from more mature geese, so the plumules are more robust and more durable. They’ll keep their loft longer than lesser down.
Down does have drawbacks, of course: It’s next to useless when wet — although it can get surprisingly damp before collapsing — takes forever to dry, and requires careful washing when dirty. On the other hand, waterproof stuffsacks are widely available, many down bags have water-resistant shells, and your tent should keep rain out.
Plumules need proper restraint. Some shells are made from a fine-weave nylon that shields you from wind but gives only modest protection from moisture that might dribble into the tent. Softer polyester microfiber shells, which are more expensive, give better wind- and water-resistance because of their fine weave and polyester’s natural disdain for water. The primo shell material for down bags (with a premium cost) is DryLoft, a thinner, highly breathable version of Gore-Tex that serves as an effective last line of defense against water. It’s available as an option on many bags if you’re willing to pay up to an extra C-note. And some makers are using new shell treatments to add water-repellency without reducing breathability or adding much cost.
Fit and finish
Sleeping bags come in three basic shapes: mummy, semirectangular, and rectangular. A mummy bag is the warmest because it leaves the smallest space for your body to heat up and minimizes the opportunity for cold air to seep in. But if you sleep in a fetal (knees-up) position, or like to move around, consider a semirectangular. It tapers at the feet for warmth but gives knees and elbows room to roam. A rectangle is roomier, but requires more energy to make warm. The following bags all hum the mummy theme — nothing rectangular here — but they differ in width and degree of taper. As for length, buy a bag that’s just long enough for your body (most bags come in regular and long; some also come in short). You pay extra for a longer bag, it requires additional energy to keep warm, and it weighs more.
Finally, it’s worth noting that some manufacturers are making women-specific sleeping bags that are shorter, narrower in the shoulders, and wider in the hips for a more thermally efficient fit. Some also place extra insulation in the torso area and the footbox.
Look for neat stitching throughout the bag and, in the case of down, chambers that aren’t leaking feathers. The draft tube (insulation that overlaps the zipper) should lie flat. If you camp in chilly weather, look for a bag with a draft collar (it goes around your shoulders). And seek a hood with plenty of insulation and a contoured fit. Don’t quibble over a couple of ounces in weight. More important is stuffability: My favorite bag stuffed to the size of a cantaloupe.
Unless noted, each bag reviewed here is rated to 20 degrees. Prices and weights are for regulars; add $10 to $20 and four to eight ounces for longs.
Proper cleaning and storage is the key to keeping your backwoods bed cozy for many camping seasons. Here’s how to prevent a sleeping bag from shriveling prematurely.
Shake that thing. If it’s a down bag, really shake it: Hold by one end and let fly for a minute or two. That fluffs and redistributes the insulation, filling in potential cold spots. Give a synthetic bag a brief shake for the same reasons, but don’t overdo it: You might tear the insulation.
Protect it from you. On the trail, use a ground cloth and pad under your sleeping bag to protect it from dirt and dampness. And, because most people sweat out a pint of water or more during the night, wear long underwear or use a bag liner (Design Salt makes a very light one from Egyptian cotton for $36) so the sweat and grime from your skin doesn’t infiltrate the lining. Then turn your bag inside out every morning to let any absorbed moisture evaporate.
Do wash. Washing your bag will not only neutralize sleeping bag halitosis but also will restore loft and warmth. Use an oversize, front-loading washer; down requires a special soap or a mild cleaner like Ivory Snow. Run the load on gentle and put the bag through rinses until the water is soap-free. Then use a large dryer at a low setting; with down, toss in a few clean tennis balls to break up clumps.
Give it room to breathe. Never store your bag, even for a few weeks, in its stuffsack — all that compression tends to break down the insulation. After each trip, air the sleeping bag thoroughly for several hours, then place in a breathable, loose-fitting sack and store where it won’t get smushed.