AntiGravityGear Stratum 55 Top Quilt Review
The AntiGravityGear Stratum 55 Top Quilt ($69) is a no-frills, lightweight, and inexpensive backpacking quilt stuffed with 800 fill power down and rated to 55*F, for those nights when it’s too chilly to just sleep in your clothes or a sleeping bag liner, but too warm for a 3-season quilt. It can stand alone as a summertime quilt or be combined with other insulation as part of a cold-weather sleeping system.
Specs at a Glance
- Temperature Rating: 55*F / 12.8oC
- Weight: 17.2 oz / 488 g
- Quilt Dimensions: 74″ long x 46″ wide (at the top, the quilt’s widest point)
- Stowed Dimensions (in stuff sack): 10″(length) x 5″ (diameter)
- Shell Material: 46% Nylon / 54% Polyester
- Contents: 800 Fill Power Down with “10% +” Overstuff
- Pad attachment: None
- Drawcords: None
- Footbox: Sewn closed
No Frills Design
The AntiGravity Gear Stratum 55 Top Quilt is about as simple as a quilt can be. The only design feature is a sewn footbox. This means you can’t open it up and lay it flat like a comforter, which is nice in hot weather, but it’s easy to kick your feet out from the Stratum’s footbox if you get too hot. There are no snaps, straps, pad attachments, or drawcords anywhere on the quilt, resulting in light weight and ease of use. This simplicity translates especially well to hammock use. On a night in a hammock that started in the eighties and dropped to the sixties (Fahrenheit), I was able to grab the Stratum from where it was balled up at my feet, find the footbox by feel, and pull the quilt up over me, without having to turn on my headlamp.
The Stratum comes with a simple stuff sack with a surprisingly thick cord and big cordlock. When stuffed, the package is compact at 10 inches long by 5 inches wide (diameter), almost exactly the size of my 12-ounce hooded puffy jacket in its stuff sack. The quilt does not come with a large breathable storage sack, which you’ll want to purchase to preserve the loft of your quilt for the long haul while at home. AntiGravityGear sells one separately, as do a number of other vendors, or a cotton laundry bag works just fine.
With a shoulder girth of 46″, the Stratum 55 is a relatively narrow quilt, best used in a hammock and by people with a slim build. For example, when ordering a pre-made, non-custom top quilt, most quilt vendors sell 50″ wide quilts for hammock users and 55″ wide quilts for ground users.
If you’re in doubt about the shoulder girth you need and whether the Stratum 55 would suit you, measure the circumference of your shoulders with your arms hanging loosely by your side. If you sleep on your back in a hammock and don’t toss and turn at night, then the Stratum will fit you if your girth is equal to or less than 46″. If you thrash and roll around at night, sleep curled up on your side, or sleep on the ground, add 5″ to your shoulder girth measurements to get an indication of the top quilt width you require.
Fill and Construction
The AntiGravityGear Stratum 55 Top Quilt is stuffed with 800 fill power down with approximately 10% overfill (AGG calls it “10% +”). Overfill is extra down beyond what would be expected for a specific temperature rating, and it serves two purposes: it helps make the temperature rating more conservative (recognizing that warmth is highly subjective.) On warm weather quilts with less down, the extra fill can prevent the down from shifting and causing cold spots with no insulation. The Stratum has a sewn-thru quilting construction that also serves to keep the down in place. Sewn-thru construction is simpler and less expensive than the box-baffled design found on colder-weather quilts and sleeping bags, but some heat can escape at the seams. However, for a quilt made for the summer, a sewn-thru design makes sense.
The combination of these two design elements resulted in a quilt that felt loftier than I would have expected from its temperature rating. Each of the boxes in the quilted grid pattern felt plumply stuffed.
Use as part of a cold-weather sleeping system
The quilt’s simple design makes it ideal to use as a liner or insulating filler inside a multi-bag or multi-quilt cold-weather insulation system. Stacking quilts and sleeping bags is an effective way of pushing the gear you have into colder temps without purchasing single-purpose, very expensive cold-weather sleeping bags. The Stratum can be used as a liner with cold-weather quilts or sleeping bags with lots of girth to add another 15* or so of warmth. Practice this on low-intensity, easy-to-bail-from trips or backyard winter experiments before trying it out in the backcountry.
If you find you consistently roast in your current bag on summer trips, the AntiGravityGear Stratum 55 Top Quilt is a low-cost way of increasing your comfort and decreasing your pack weight, provided that you have a slim build can fit into its narrow dimensions. The Stratum 55 also provides a good way to experiment with multi-bag layering systems when used as a cold-weather liner bag. We’d also like to see AntiGravityGear offer a shorter length version of the quilt for shorter adults, teens, and scouts, who we feel are underserved by existing top quilt manufacturers.
Disclosure: AntiGravityGear provided the author with a quilt for this review.Editor's note: Help support this site by making your next gear purchase through one of the affiliate links above. Click a link, buy what you need, and some sellers may contribute a small portion of the purchase price to support SectionHiker's unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.