Our Verdict
Compare to Similar Products
Awards | ![]() | ![]() | ![]() | ![]() | ![]() |
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Price | $109 List Check Price at REI | $145 List | $130 List | $75 List | $55 List Check Price at REI |
Overall Score ![]() |
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Star Rating | |||||
Pros | Superior breathability, excellent warmth, long zip neck for venting, durable construction, comfortable micro grid fleece interior | Breathable, excellent thermoregulation, extra warmth with hood, easy to layer | Cozy fleece interior, easy to layer, warm, versatile, stash pocket, kangaroo pouch, high quality | Affordable, thumb loops, long cut, easy to layer over top, soft and durable fabric | Affordable, thumb loops, soft fabric, great fit, durable |
Cons | Fabric holds odor, thumb loops lack quality, not a thermal weight despite name | Expensive, takes a few washes to increase next-to-skin comfort | Expensive, not super breathable, boxy updated fit | Material is not midweight | Tightly woven fabric doesn't breathe very well, smelly |
Bottom Line | Outstanding warmth and breathability make this layer one of our favorites for high output mountain activities | A top-notch lightweight performer featuring exceptional thermoregulation and breathability with an innovative Merino wool technology that gets softer with every use | This high performance synthetic layer is ready for pretty much any adventure you dream up | This affordable base layer features ultra fine Merino wool fibers that are super comfortable next to your skin, effectively wick away moisture, and remain odor-free | This durable base layer features a soft and stretchy fabric and a slim fit for a variety of activities, all for an affordable price |
Rating Categories | Patagonia Capilene... | Black Diamond Solut... | Arc'teryx Rho LT Zi... | Ridge Merino Aspect... | REI Co-op Midweight... |
Warmth (25%) | |||||
Breathability (25%) | |||||
Comfort and Fit (20%) | |||||
Layering Ability (20%) | |||||
Durability (10%) | |||||
Specs | Patagonia Capilene... | Black Diamond Solut... | Arc'teryx Rho LT Zi... | Ridge Merino Aspect... | REI Co-op Midweight... |
Fabric Weight | Midweight | Lightweight | Midweight | Lightweight | Midweight |
Measured Weight | 6.1 oz | 6.6 oz | 7.5 oz | 6.0 oz | 7.5 oz |
Material | 92% recycled polyester, 8% spandex | 78% Merino wool, 22% polyester | Torrent 190 (84% polyester, 16% elastane) | 84% Merino wool, 16% nylon | 92% polyester, 8% spandex |
Avaliable Cuts | Zip neck | Crew, 1/4 zip neck/hoody | 1/4 zip, crew, hoody | Crew, 1/4 zip | Crew, 1/2 zip neck |
Odor Control Fabric | Polygiene permanent odor control | Naturally odor resistant | Polygiene | Naturally odor resistant | None |
Thumb Loops? | Yes | Yes | No | Yes | No |
UPF (sun protection) | No | No | No | 50+ | 50+ |
Length | Medium | Medium | Medium | Long | Medium |
Fit | Regular fit | Runs small | Trim fit | Slim | Fitted, true to size |
Accessory Pocket? | No | No | Yes | No | No |
Flat-lock Seams? | Yes | Yes | Yes | Yes | Yes |
Our Analysis and Test Results
When considering the Thermal Weight Zip-Neck, the first thing to do is acknowledge that this layer should not be called a thermal weight as advertised, but rather a midweight base layer appropriate for cool to cold weather conditions. However, it does offer superior warmth and breathability thanks to its lightweight and synthetic design. The Polartec fleece traps a surprising amount of body heat, while the long zip neck and microgrid design successfully allow the garment to vent and release moisture. While we wish that Patagonia did a better job with the elastic thumb loops, they do help when layering this top with others in your cold-weather kit. If you're looking for a high-performing synthetic midweight base layer, this one doesn't disappoint.
Performance Comparison
Warmth
As we've already mentioned, this layer should not be considered a thermal weight; however, it does trap an amazing amount of body heat. We noticed how well the Thermal Weight Zip-Neck performed once the temperatures dropped when in Yosemite Valley and as it snowed on another trip to Utah. We took this layer for extended trail runs to Glacier Point and up the Snow Creek steps before selecting it to keep us warm for three cold October nights sleeping on the side of El Capitan.
Our testers benefited from features like the Polartec power grid fabric, the drop tail hem, and the soft micro-grid fleece interior, which kept us warm (even sometimes too warm!) during our fall adventures. The zip neck, thumb loops, and slim fit of this base layer also contribute to its top-notch warmth by allowing the garment to sit close to your skin and remain in place even while in motion. While not the warmest synthetic layer we've tested, nor a true thermal weight as advertised, this base layer is warm enough to be worn on its own during shoulder season adventures or at the base of a layered system during those bone-chilling winter months.
Breathability
The Thermal Weight Zip-Neck really shines in the breathability category thanks to the fabric's open grid pattern that is practically see-through when held up to sunlight. The long and centered zip neck contributes to this layer's high scores in this metric, allowing a choice between containing body heat or further releasing sweat built up during intense activity.
Our lead tester was grateful to have selected this top when climbing in Yosemite in late fall due to its high performance and versatility. Early in the morning, when the sun was shining, and the winds were calm, we noticed this layer effectively released any built-up sweat. Later in the day, when the clouds rolled in and the wind picked up just below the summit of El Capitan, our lead tester remained warm, thanks to the effective square-patterned fleece insulation. If you're looking for a warm base layer that also successfully wicks moisture away from your body, this is a great pick.
Comfort and Fit
It is clear that Patagonia put a lot of consideration into this lightweight base layer's overall comfort and fit. The Thermal Weight Zip-Neck is a slim-fitting layer with offset shoulder seams to prevent chafing when carrying a heavy pack. The design features internal neck tape and flatlock seams for increased comfort.
This layer's 92% recycled polyester creates a soft feel next to the skin, and the 8% spandex provides enough stretch for full range of motion. In terms of fit, our testers appreciate the gusseted underarms and drop tail hem for increased coverage and warmth, especially when engaging in activities like rock climbing. Ultimately this slim-fitting base layer feels comfortable next to the skin, and the polyester spandex fabric combination allows for ease of movement, no matter what adventure you have up your sleeve.
Layering Ability
Thanks to a smooth face fabric and stretchy spandex material, it is easy to layer over the top of the Thermal Weight Zip-Neck. However, due to its rather slim fit and the square grid pattern on the interior, our testers found it difficult to layer more than a tank top or lightweight base layer crew underneath.
While we love that the Thermal Weight Zip-Neck offers a thumb loop feature to aid with layering and warmth retention, we wish the design wasn't so minimal. Some of the other layers in this review feature thicker, higher quality, and more comfortable thumb loops, while those on the Thermal Weight are just very thin and elastic. These lack the comfort and warmth we'd hope for after investing in a more expensive base layer.
Durability
While we are happy to report that we did not experience any durability issues during our extensive testing period, we have a couple of complaints regarding odor control and the minimalist thumb loop construction of this layer. Patagonia boasts a permanent odor-free Polygiene treatment, but this layer still holds on to body odor, especially after several days of use. To be fair, this has been the case for all synthetic layers that we've tested — Merino wool is simply superior in odor protection across the board. That said, the air-permeable fabric of the Thermal Weight, along with the long zip neck, are helpful at reducing odor, however, it does still linger in the fabric once the wind dies down.
Our testers were also disappointed by the lack of effort that Patagonia put into their thumb loop design, which they refer to as "low profile." We found that the thin elastic construction of the loop not only reduces comfort but doesn't inspire confidence that they'll continue to be functional throughout the life of this base layer. These complaints aside, we experienced no serious issues with the Thermal Weight Zip-Neck during testing, whether on a long trail run or hauling a heavy load up a rock face.
Should You Buy the Patagonia Capilene Thermal Weight?
While not the most affordable synthetic base layer, our testers feel this layer delivers higher performance than the price tag would suggest. This layer successfully traps heat and wicks moisture incredibly well, thanks to a Polartec and spandex construction that feels soft next to the skin. If you're allergic to wool and seeking a synthetic option for your cold-weather mountain pursuits, this layer is worth the investment.
What Other Base Layers Should You Consider?
While our testers love the synthetic Capilene Thermal for its superior warmth and breathability, more affordable options are available, such as the Patagonia Capilene Midweight Crew. Or, if you'd like a versatile blended design that offers high performance without the smelly synthetic construction, check out our favorite Merino layer, the Black Diamond Solution 150 Merino Quarter Zip.
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