Guest - Not logged in 

Reviews > Sleep Gear > Sleeping Bags > Slumberjack Vertex 20F Sleeping Bag > Test Report by Sheila Morrissey



Photo from manufacturer's website

Initial Report - December 19, 2007
Field Report - February 18, 2008
Long-Term Report - April 15, 2008

Initial Report: December 19, 2007

Name: Sheila Morrissey
Age: 27
Gender: Female
Height: 5 ft 8 in (1.7 m)
Weight: 155 lb (70 kg)
Email Address: geosheila(at)yahoo(dot)com
City, State, Country: Goleta, California, USA

I have been backpacking since 2005. Most of my trips have been from one to three nights in length on trails in the Sierra Nevada or Los Padres National Forest. My pack typically weighs around 25 lb (11 kg), including consumables.

Manufacturer: Slumberjack
Model: Vertex
Temperature Rating: 20 F (-7 C)
Year of Manufacture: 2007
Manufacturer’s Website:
MSRP: N/A   
Listed Weight: 3 lb 4 oz (1.5 kg)
Measured Weight: 3 lb 4.1 oz (1.48 kg)
Listed Dimensions: 32 in x 82 in (81 cm x 208 cm)
Measured Dimensions: 32 in x 82 in (81 cm x 208 cm)

The Slumberjack Vertex is a mummy-shaped sleeping bag rated to 20 F (-7 C). The liner is polyester taffeta, which feels like the same slippery material I've seen on many sleeping bags. The outer shell is nylon diamond ripstop and polyester pongee. The diamond pattern is only visible up close and this outer material feels softer than the liner material. The Vertex is filled with Climashield XP continuous filament insulation. Care instructions on the bag indicate that it should be washed in warm or cold water with mild detergent in a front-loading machine. It can be tumbled dry below a temperature of 120 F (49 C).


The bag is only available in one color combination: "dark navy/rage/stone/charcoal". The inside liner of the bag is grey (I imagine that's the "stone" color). The outside of the bag is solid dark blue on the underside with charcoal stripes up the sides, and the bag has a navy, charcoal and "rage" (looks like safety orange to me) pattern on top. "Slumberjack" is written in blue embroidery across the 



The hood of the Vertex easily flips inside out, which Slumberjack says, "gives users the option of a flat hood or a fully contoured hood." In its non-flipped position, the hood can be tightened with two drawcords; One drawcord is drawn through the top of the hood, which draws the hood down over my forehead, and a second drawcord is drawn through the sleeping bag material under my chin. The upper drawcord is flat and the lower drawcord is rounded, supposedly "allowing users to easily adjust storm collars and hoods in low light situations." Both drawcords are locked in a single barrel-lock closure.



Inside the sleeping bag is a small pocket with a hook-and-loop closure. Slumberjack calls the pocket an "internal media pocket".


When the bag is fully zipped, the zipper is secured with a hook-and-loop tab. An insulated draft tube runs along the length of the zipper. Thicker nylon material (the black material in the photos below) on the outside of the draft tube supposedly offers "anti-snag zipper protection".



The Vertex's zipper reaches to about 16 in (40 cm) from the foot end of the bag. The footbox has a trapezoidal shape for a more comfortable foot position. In the photos of the footbox below, it almost looks as if someone's feet were in the bag, but it is empty.



The Vertex came with an orange ("rage") compression sack made of the same nylon diamond ripstop material that makes up part of the outer shell of the sleeping bag. The bag can be easily stuffed into the compression sack, but the bag can only be compressed slightly.


The Vertex sleeping bag looks just like the photograph on the Slumberjack website. What I didn't realize from the website is that there is no draft tube around my shoulders. The hood cinches down tightly, but during this test I will be looking into how well it keeps cold drafts out of the bag. I should have realized this from the measurements listed on the website, but I was a bit surprised to see just how big this bag is. When my feet are at the bottom of the bag, the hood is loose enough that I could put a full-sized pillow inside of it with me. The width of the bag is huge, too. I mean really, really huge. I was able to rather easily zip the bag closed with both me and my 60-lb (27-kg) dog inside. I've never attempted that before! I'm guessing the generous width of the bag will be comfortable, but this bag is so huge that I'm a little bit concerned about whether I'll be able to heat up all this extra space. The only part of the bag that doesn't feel big is the footbox. On the one hand, a more snug footbox should help me keep my feet warm, but I will be interested to see how comfortable the footbox is.

Field Report: February 18, 2008

I used the Vertex on two overnight backpacking trips in Los Padres National Forest. On the first trip, I camped at an elevation of about 4,500 ft (1,370 m) and slept inside a tent on an insulated backpacking air mattress. The night was clear and the temperature was about 35 F (2 C). On the second trip, I camped at an elevation of about 2,000 ft (600 m) and again slept inside a tent on an insulated backpacking air mattress. There was a lot of rain during the night and the low temperature was about 40 F (4 C).

When temperatures were just above freezing, I was uncomfortably cold, even wearing wool socks, pants, a fleece jacket and a beanie. It wasn't until after I let my dog inside the bag so we could both warm up that I slept comfortably enough, with only my feet feeling cold. When nighttime temperatures were about 45 F (7 C) in the evening to 40 F (4 C) by early morning, I was warm enough when I went to bed wearing thick wool socks, two layers of pants, three shirts and a beanie. As the night got cooler, I intermittently woke up feeling cold. So for me, the lower temperature limit of this sleeping bag is about 40 F (4 C).

Temperature ratings on sleeping bags are, of course, extremes and do not indicate the temperature at which a bag will be comfortable. I find that I personally usually like my sleeping bags to be rated about 15 F (8 C) degrees cooler than the actual nighttime temperature. Unfortunately, the Vertex is rated to 20 F (-7 C), but definitely didn't keep me warm at 35 F (2 C).

I believe there are two reasons the Vertex isn't warm enough for me: (1) it doesn't have a shoulder draft tube and (2) the bag is way too huge for me. Without a shoulder draft tube, I am forced to cinch the hood closed to keep drafts out of the bag. However, because the bag is so huge, I found that I rolled around inside the bag without turning it. I woke up in a panic several times because I was breathing stuffy air and couldn't find the cinched hood opening. The obvious solution was to loosen the hood. Of course, that meant that cold air could get in the bag. The ClimaShield insulation in the Vertex might well be warm enough for temperatures of 40 F (4 C) or 35 F (2 C), but the lack of a shoulder draft tube and the loose fit of the bag kept me too cold.

Next time I'm going to try playing around with the two drawcords. I always just equally tighten both the cord that tightens the bag under my chin and the cord that tightens the bag over my head. Perhaps I can get the bag tighter around my shoulders without cinching the hood all the way.

I still cannot believe how huge this bag is. I was able to zip the bag shut with me and my 60-lb (27-kg) dog inside of it and I even tightened the hood. I was warmer that way, but my feet got cold in the big empty space inside the bag and I'm pretty grossed out by sharing a sleeping bag with a dog. When my dog stayed home, I had a hard time warming the entire huge bag myself. Though the giant size of the Vertex might be a benefit for someone else, I'm wishing I had a tighter-fitting sleeping bag.

For me, the Vertex was only comfortable at temperatures above 40 F (4 C). Other bags that I have used that were comfortable at the same temperatures weighed the same or less than the Vertex. So far, I'm not certain that the 3 lb 4 oz (1.5 kg) Vertex is worth it for me.

The Vertex seems to be well constructed and I haven't noticed problems in any part of it. I managed to get the zipper stuck a couple of times, but I found that the "anti-snag zipper protection" really does work great and I got the zipper unstuck easily. Stuck zippers really bother me, especially when I'm trying to get out of a sleeping bag, so I think the smooth zippers of the Vertex are just fantastic. The shell of the bag is also wonderfully constructed. The outside of the Vertex got quite wet when I slept leaning against the side of tent while it was raining outside. For the most part, the water beaded up on the shell and I didn't feel any moisture inside the bag.


My earlier description of the compression sack wasn't completely fair. Compressing the bag after stuffing it squeezes it down about 4 in (10 cm), which definitely helps with the bag's packability. This isn't the lightest or most compressible bag I've used, but it does have more insulation than the lightest and smallest bag I've used and it definitely fits easily inside my pack.

Long-Term Report: April 15, 2008

I have now used the Vertex for a total of eight nights. During the long-term testing period, I used the Vertex for three nights of backpacking and three nights of car camping in southern Utah and northern Arizona. I spent one night on a dirt road in Dixie National Forest just outside Grand Staircase-Escalante National Monument, two nights in Coyote Gulch, one night at a Paria River trailhead, one night in Buckskin Gulch, and one night on a dirt road in Kaibab National Forest just outside Grand Canyon National Park. The elevations were near 7,000 ft (2,100 m)
the first and last nights, and were between 4,000 ft (1,200 m) and 5,000 ft (1,500 m) all the other nights. The temperature was 23 F (-5 C) in Dixie National Forest and was between 35 F (2 C) and 40 F (4 C) the other nights. All nights were spent on an insulated air mattress inside a tent.

I tested the Vertex near its temperature limit the first night and suffered for it. With a temperature of 23 F (-5 C), I didn't get a wink of sleep, even wearing two pairs of wool socks, a balaclava, two layers of pants, three shirts and a fleece jacket. I got up with the sun and wasn't able to feel my freezing feet for more than an hour after getting up. It was awful.

Because of my bad experience, and because I was uncertain what temperatures to expect in Coyote Gulch, I borrowed my hiking partner's sleeping bag liner for our 3-day Coyote Gulch backpacking trip. Although nighttime temperatures were warmer on that trip, I was most comfortable using the Vertex with the sleeping bag liner. However, I was absolutely not comfortable carrying extra weight on that trip. I don't know for certain what the liner weighed, maybe an extra 1 lb (0.5 kg), but I'm really annoyed I felt the need to carry a liner for extra warmth when I was already carrying the fairly heavy 20 F (-7 C) Vertex. In addition to using the liner, I wore multiple layers of clothing and stuffed what little other clothing I had at the end of the super-long sleeping bag to fill some of the huge void and keep warm each night. I left the liner behind on my Buckskin Gulch trip and slept warm enough with my many layers of clothing. Still, throughout this test, no matter how I tightened the bag, I couldn't get the hood to fit well and I could not keep cold air from entering in big drafts behind my shoulders. I won't use this bag for backpacking again. I'm not even convinced it was designed for backpacking because of its nearly rectangular and not very heat-conserving shape. It certainly wasn't designed for backpacking use by someone of my size.

At the end of long-term testing period, I finally gave this sleeping bag its first washing. However, just before I threw it in the machine though, I noticed that the charcoal-colored material around the hood and down the sides of the Vertex is fraying already. I did wash the bag carefully in a large front-loading machine at the laundromat
following the instructions on the bag, but the material only suffered more in the wash.

The Slumberjack Vertex 20 F sleeping didn't work out well for me for backpacking. The bag is way too big for me, which made it too cold and too heavy. I especially wished this bag's hood would have fit more snugly and that there was a shoulder draft tube. I might keep the Vertex around for comfortable summer car camping, but definitely won't use it again for backpacking and couldn't recommend it to others. 

  • Zipper slides easily and rarely gets stuck
  • Shell repels moisture well
  • Zipper draft tube works well
  • Bag is huge and I imagine it would be comfortable for summer car camping
  • No shoulder draft tube
  • Hood doesn't fit snugly letting in cold air
  • Bag is too long and too wide making it too cold for me
  • Bag is only comfortable down to about 40 F (4 C)
  • Bag is heavy compared with other bags that are comfortable at 40 F (4 C)
  • Charcoal-colored material is starting to fray
This concludes my Test Series. Thank you to Slumberjack and for providing me with the opportunity to test the Vertex 20 F sleeping bag.

Read more reviews of Slumberjack gear
Read more gear reviews by Sheila Morrissey

Reviews > Sleep Gear > Sleeping Bags > Slumberjack Vertex 20F Sleeping Bag > Test Report by Sheila Morrissey

Product tested and reviewed in each Formal Test Report has been provided free of charge by the manufacturer to Upon completion of the Test Series the writer is permitted to keep the product. Owner Reviews are based on product owned by the reviewer personally unless otherwise noted.

All material on this site is the exclusive property of
BackpackGearTest software copyright David Anderson