My first sleeping bag was liberated from my dad’s musty military kit. With incisor-sized zipper teeth and a jumar for a slider, the M-1949 was more of a feather bed than a mummy bag. Weighing in just under eight pounds, it had the deadweight of a futon mattress and siphoned moisture like ShamWow®. Fortunately I had an external-frame pack to strap its bloated mass to.
Weight begets weight, and a sleeping bag (next to the tent and pack) is one of the top three perps to consider when lining up guilty pounds. While there have a been significant advancements in insulation (…down curated from the abandoned nests of free-range Elder ducks by gluten-free Gaelic hermits…), like any decision made when going light, you cut that which doesn’t contribute. And this is where the quilt rises above the fill.
The quilt is a simple concept; it’s a fitted duvet that wraps around your body, leaving the superfluous on the workroom floor…including the zipper, hood, and most noticeably, the underside insulation. At first blush, this backside exposure appears to channel all the accouterments of a hospital gown, but the design has a lot going for it.
Insulation alone does little to keep you warm—it lofts, trapping heat radiated by your body. Compress it—by, say, sleeping on it—and insulation loses its heat-trapping qualities, leaving you to haul the deadweight. But a foam or air pad resists compression and is a great insulator. And since a backpacker always brings a pad, the quilt leverages the thermal efficiencies of both the underlying pad and top loft, and scraps overlapping structures.
At the risk of hanging it all out, intelligently designed quilts eliminate the dead-air space between you and the quilt, putting your BTUs to work for you. Manufacturers tackle this in a few ways.
First and foremost, a quilt needs to integrate with a pad to reduce escaping heat. Most quilts on the market—like those from GoLite and Therm-a-rest—have two to three straps that wrap the quilt around the pad. For those who toss in their sleep, this gives you some wiggle room. Other quilts, like Katabatic Gear, use a cord-lock solution where the quilt straps on top of the pad, tucking the sidewalls between you and the pad.
A quality quilt will have a differential cut between the shell and inner liner. It’s a bit like a tailored suit versus an off-the-rack fit; a differential cut will contour to the body’s shape, reducing baggy ‘draft channels’ between you and the pad. A draft collar, elastic trim and lightweight snaps can reduce heat from top-spilling around the neck. And baffled design, as opposed to sewn-through construction, will reduce cold spots with a continuous layer of insulation. Lastly, most quilts have a “foot box”, enclosing the feet and lower legs, allowing the wheels to comfortably recover after a long day on the trail.
At first blush, the quilt might appear to be a niche tool with limited range. But it’s exactly its simplicity that contributes to its wide versatility. In summer, I’ll make do with just my clothes worn and a 30F quilt; if I get too hot, it’s easy to vent. In the shoulder seasons, I’ll cinch the quilt down to the pad and extend its comfort range with a hat or balaclava—roughly 6 percent of our body heat is lost through the head! Come winter, I’ll always bring an extra full-length pad and integrate my parka, insulated pants and booties into my sleep system. So with one 18-ounce, 30F quilt, I’m covered between 15-50F.
That military bag? It’s relegated to my father’s bunker. But I now watch my own kids playing with my ‘vintage’ mummy bags, circa 1992—two-way zippers, hoods, draft tubes and all. Meanwhile, the quilt has stepped up to meet 90% of my outdoor demands where it’s likely to stay…that is until the Gaelic hermits manage to harvest Helium infused down….