The Mountain Hardwear HyperLamina Spark 35 is rated in the US market as a 35° F bag, but you'll see 32° F all over it because that's its EU Lower Limit rating. In our tests it was pretty comparable to most 35° F bags. You'd have to layer up if you wanted to use it in temperatures much colder.
Check out the Overall Performance chart below to see where the Spark 35 landed amongst the competition in our backpacking sleeping bags category.
The Hyperlamina Spark 35 is rated at 35°F for their US market, despite being labeled as a 32°F on most of its attached literature (and its storage and compression sack). This is because it has an EU Temperature Limit of 32F (or the EU's Men's Temperature Rating). Overall, we found that this bag was pretty average in warmth among other 35°F synthetic or down bags. In our side-by-side testing, the Spark 35 wasn't as warm as any of the 30°F models, but also wasn't FAR
colder than a handful of models.
We do think if your body temperature runs low, this bag might only be good to 40°. Mountain Hardwear uses an insulation called Thermal Q, with a 60 gram layer. What does that mean? Thermal Q is a proprietary insulation made by Mountain Hardwear and used in several models of their sleeping bags and jackets. It is one of the lighter and more compressible synthetic fabrics, but is slightly less long lasting than other synthetic materials.
The Mountain Hardwear Hyperlamina Spark 35 offered pretty average warmth for a 35F bag but you'd certainly want to add layers for anything colder.
If you're after the warmest bag in our testing, the Western Mountaineering Megalite
, Western Mountaineering Ultralite
, Marmot Hydrogen
, and REI Co-op Igneo 17
are all respectable options, depending on your budget and any other must haves (such as comfort, packed size, versatility, etc.).
At 1 pound 12 ounces, the Spark 35 is one of the lightest synthetic bags on the market, given its temperature rating. If you frequently camp in wet environments, where it would be best to take a synthetic bag, but you weren't necessarily looking for one due to its larger packed size and heavier weight, this might be the bag for you. It's around a pound lighter than the warmer 20-degree Cat's Meow (2 lbs 11 oz) and about the same weight as the Western Mountaineering Ultralite
and REI Igneo 17
Part of the reason the Hyperlamina is so light is its high quality synthetic fill, fairly low-weight 22D nylon shell, and half length zipper; the zipper shaves 2-3 ounces off versus using a full-length zipper. Compared to the three pound Kelty Tuck 20
, which didn't really feel much
warmer, the Hyperlamina Spark 35 is half the weight, but also twice the price. Even compared with closely rated down bags, the Spark 35 doesn't give up much; in fact, it's lighter than the Nemo Salsa 30
(2 lbs 1oz) and the Kelty Cosmic Down
(2 lbs 9 oz). Basically, it's one of the lightest 30-35°F synthetic bags that are currently available.
The Mountain Hardwear Hyperlamina Spark 35 (far left) compared with several other performance oriented bags. As you can see the Spark 35 compresses extremely small by any account but especially for a synthetic bag. The Spark 35 (far left) compared with several other bags from left to right; The Nemo Salsa 30 (second from left), REI Igeno (center), Marmot Hydrogen, and Western Mountaineering MegaLite.
Besides being one of the lightest synthetic bags, the Spark 35 is also easily one of the most packable options (of its temperature rating) on the market today. Check out the chart below to see where this bag scored in Packed Size compared to it's competition.
The Spark 35 packs down smaller than several down bags like the Nemo Salsa 35, Kelty Cosmic Down 20, or Sierra Designs Backcountry Bed 600 3-Season
, and is even comparablable to performance oriented bags like the Western Mountaineering MegaLite
and Marmot Hydrogen
, though it's around 15% bigger. The Hyperlamina Spark 35 is far smaller than the Kelty Tuck 20, or The North Face Cat's Meow
The sweet included compression stuff sack that comes with the Mountain Hardwear Hyperlamina Spark. We thought this compression sack was well sized minimizing the packed size of the bag.
We love that the Hyperlamina Spark 35 comes with a very functional compression sack, in addition to the storage sack. The compression sack fits the bag very nicely and helps to minimize the amount of space that the Hyperlamina Spark 35 will take up in your pack.
The Mountain Hardwear Hyperlamina Spark 35 offers internal dimensions that are on the wider side of mummy-style bags in our review. Here the Spark 35 (top) compared with the Sea to Summit Spark III.
Comfort, Spaciousness, and Fit
The Hyperlamina Spark 35 offers wider than average dimensions compared with most backpacking-oriented mummy-style bags in our review and on the market. It offers near identical dimensions as our Editors' Choice the Western Mountaineering MegaLite and was one of the more comfortable bags that we tested. While it offered fairly spacious dimensions, we never felt like the bag was too big; in the case of a bag being too big, cold spots have the potential to be created. We did not face this issue when using the Spark.
Most side and tummy sleepers could get their knee pretty high while sleeping in this bag. We found it to offer a high level of comfort among contenders we tested, especially for those who sleep in positions other than on their back. The Hyperlamina Spark 35 features a comfortable 22D fabric for its lining, which was above average for its feeling against our skin. We liked the interior fabric of the Spark 35 better than the Cat's Meow, Nemo Salsa 30, or Kelty Tuck 20.
The Mountain Hardwear Hyperlamina Spark 35 (left) is on the wider side and its' dimensions are close, but weren't quite as big as The North Face Cats Meow (center) or Kelty Cosmic Down 20 (right).
The Mountain Hardwear Hyperlamina Spark 35 is a fairly versatile bag. It's spacious enough for car-camping, light enough for most backpacking trips, and its synthetic fill helps it excel in both wet and dry climates. The half-zipper offered plenty of ventilation; slightly to our surprise, we never felt it was a hindrance during our real-world testing.
We do think that in warmer weather, the Hyperlamina might be a bit more difficult to use as a blanket, as you can't open it all the way up. In temperatures that dip below 35°F, the Spark offers plenty of shoulder space, which allows the user to wear additional layers.
The Mountain Hardwear Hyperlamina Spark 35 is a pretty no frills bag, instead focusing on minimizing weight and comprehensibility. The Spark 35's half length zipper saves a few ounces over a full length zipper and offers enough ventilation to be used in a wide range of overnight temperatures. In fact our testers loved the center zipper because it was so easy to get in-and-out of the bag.
Features and Design
The Hyperlamina doesn't have a lot of extra
features, as its design focuses on low weight and compressibility. Its half-length zipper shaves off a few extra ounces and we enjoyed that it was in the middle, versus having a less useful zipper of the same length on the side. We hadn't used many center zip style sleeping bags previously and were a little skeptical; however, after several days in the field, nearly all of our testers loved the design. It's just plain easier to unzip, sit up in, and perform daily activities in. The hood is basic, yet well-designed, and is effective and comfortable. For a bag that offers more features, consider the Sea to Summit III
or Nemo Salsa 30
The synthetic fabric used in the Hyperlamina is super light weight and compressible, but is slightly less durable than other synthetic fabric; it will likely lose around 20% of its warmth when you hit the five year use mark.
Hyperlamina 35 Versus Treated Down Bags
When we did our untreated down versus non-treated down comparisons, there was a minimal amount of difference in water-resistance and drying times. In our testing, all of the synthetic fabrics were more water resistant and offered far quicker drying times, drying in about 20% of the time as treated hydrophobic down bags that we tested (during our complete soaking test).
The Mountain Hardwear Hyperlamina Spark 35 is a super versatile bag; its spacious enough for car camping and shorter trips, but is light and compact enough for long range adventures. It vents decently well, but is roomy enough in the shoulders to add extra layers on 30 F and below nights.
The Hyperlamina Spark 35 is probably the best summertime 3-season backpacking synthetic bag we have seen. Each tester who used the bag absolutely applauded how light and compact it was for a synthetic bag. We remain amazed by its low weight and fantastic packed size, as it's comparable to average and slightly above average down bags in many ways. If you want a warmer bag to use regularly around 30°F and below, we'd go for The North Face Cats Meow
, which is noticeably warmer and rated to 20°F.
Value and the Bottom Line
The Hyperlamina Spark 35 is comparable in weight and packed size to that of many down bags with 700+ or lower down fill power. That said, it is also comparable in price to many of those bags and it wont last as long, because synthetic fibers break down far quicker (than down), losing their warmth. If you want a synthetic bag for the climate you're traveling in, support ethical animal rights, or have allergies to down, and you want one of the highest performing synthetic bags out there, then the Spark is for you.