Patagonia Capilene Thermal Weight Bottoms - Women's Review

Perhaps one of the first considerations with the Patagonia Capilene Thermal Weight bottoms is that this is not your traditional thermal weight design. We consider these bottoms a high-performing midweight that offers superior warmth when combined with body heat and an exceptional moisture-wicking capability to keep you warm and dry. Throw in a great fit with soft and supple Polartec fabric designed to move with you, and we're sold.

Performance Comparison

Warmth

In this section, we'll attempt to clarify some confusion due to naming the Patagonia Capilene Thermal Weight bottoms because it's unorthodox that a traditional thermal weight would also appear to be see-through. The performance is in the lower bulk micro-grid fleece interior combined with exceptional breathability. The 92% recycled polyester and 8% spandex fabric combination can only provide superior warmth when combined with the loft of the open-grid pattern that wicks away moisture and keeps skin dry, even while pushing the pace in the mountains.

Is this your sedentary thermal weight base layer for the coldest months of the year? Absolutely not. The layer must work with your body heat to trap warmth and release moisture; therefore, we highly recommend this layer for year-round use. The exceptional breathability will help fight those cool mornings in the fall while keeping you dry and comfortable as the day begins to heat up — just don't forget to layer appropriately above or below these see-through bottoms. The Capilene Thermal also works great for high-output winter activities like skinning uphill or layered below some puffy pants when you're out shoveling snow. We love these bottoms for their modern spin and find their warmth sufficient when layered effectively.

Breathability

We've already touched on the remarkable breathability these bottoms have to offer. The fabric's open grid pattern allows air to easily permeate, effectively wicking away sweat from the skin before releasing it through the synthetic panels between the Polartec Power Grid design. This technology is similar to the ventilation panels offered on other models. It achieves a similar goal of keeping the body dry through an air-permeable design to increase warmth and comfort during high-output cold weather activity.

During one of our testing days, we skinned uphill in the spring sunshine and worked up a sweat before opening up our ski bibs to observe the moisture evaporating from this layer. When exposed to fresh air, the bottoms literally start releasing steam from the fabric, offloading any excess moisture to keep your body dry and cozy. The Capilene Thermal offers some of the best breathability that we've had the pleasure of testing, and we highly recommend them for a variety of cool to cold weather activities thanks to their high-performing technology.

Comfort and Fit

The Thermal Weight is hands down one of the softest and most comfortable synthetic pairs of long underwear we've tested. Patagonia's Polartec Power Grid fabric felt exceptionally cozy next to our skin, and we love the added spandex stretch to allow for a better range of motion within the recycled polyester material.

These bottoms also feature one of our favorite fits out of all the synthetic base layers tested for this review. We consider the fit true to size and find the 4" wide waistband to offer a clean design, similar to a modern high-waisted yoga pant. Within the 4" waistband is another flat elastic waistband that truly holds these bottoms in place, and on our lead tester's 5'6" frame, they sit right above the belly button. While out for a run or skiing in the backcountry, this double waistband stayed in place, but while doing yoga, we noticed it could roll over itself and require some adjustment. Since we like to spend a ton of time moving in the mountains, we love that this design features a gusseted crotch for enhanced fit and a better range of motion for various activities. Thanks to the soft Polartec fabric, stretch spandex, and flattering waistband, we're confident these bottoms will provide ample comfort and an incredible fit for most body types.

Durability

While our testers reported no durability issues during testing, we can imagine that these see-through bottoms may not withstand the test of time, especially compared to some of their competitors that feature a more rigid, tightly woven fabric. The grid pattern of the Polartec makes for an uneven and delicate surface that may be prone to rips and snags. Since they are also see-through, it is less likely that you'll be wearing these on their own, though they could be paired with shorts over top or underneath.

While Patagonia advertises HeiQ Pure odor control as an additional treatment to the polyester fabric, we did notice that these bottoms can retain some odor over time. This is true of most synthetic fabrics and is often a trade-off for their increased durability compared to Merino wool.

Drying Speed

We soaked the Capilene Thermal in water, wrung them out, and hung them on a line to dry in the sunshine. We anticipated a faster drying speed due to the see-through and lightweight design, and we got it — these bottoms took just 44 minutes to dry.

After working up a sweat skinning uphill in the spring sunshine, we noticed that sweat would pool at the waistband — a common occurrence. After we returned from testing, we started the stopwatch and noted a time of only 30 minutes to dry on our body. While this isn't the overall fastest drying speed of the synthetic competitors, it's still respectable.

Layering Ability

We tested the Capilene Thermal bottoms in various layering systems and found that even though they are considered a "thermal weight," the high-performing Polartec fabric is easy to layer thanks to a smooth interface. Though these take up a bit more space, there is no friction, and no re-adjusting is needed as you move.

The waistband sits above the belly button, so it's out of the way of other layers that fasten at the natural waistline. Since they are see-through, we do not recommend the Capilene Thermal as a stand-alone piece. We found a slick bike short layered best when layering underneath, no matter the length. When considering other layers in this review that feature a design with a lower profile, we had to reduce the score of the Capilene due to the added bulk of the Polartec fabric, which is somewhat to be expected with bottoms that feature a thicker weight or open grid design.

Should You Buy the Patagonia Capilene Thermal Weight?

If you're looking for a high-performing synthetic pair of long underwear, the Capilene Thermal bottoms top our list. For a little extra investment, they offer a superior fit that includes flatlock seams and a gusseted crotch to enhance overall comfort. The soft and supple fabric is some of the most comfortable material we've tested, and we love how it feels next to the skin. The only caveat with this layer is the potential for the see-through fabric to break down faster than other rigid synthetic fibers and its ability to hold onto some body odor post-activity. But if you're after a pair of long underwear bottoms that offer ample warmth and superior breathability, these won't disappoint.

What Other Long Underwear Should You Consider?

If you're interested in another pair that can be worn as a stand-alone piece but want something more affordable, check out the Patagonia Capilene Midweight. These bottoms have a similar fit and the same waistband but feature a more rigid design due to their tightly woven polyester construction. We also consider them our favorite for optimal durability and year-round use. Alternatively, the Minus33 Franconia Midweight Wool is an affordable 100% Merino wool option with a super soft next-to-skin feel and a looser fit. And for optimal year-round performance — complete with body-mapped ventilation panels — consider the Icebreaker 200 ZoneKnit Merino Leggings, our absolute favorite Merino option. And if you're interested in a Merino wool and synthetic blend, the Smartwool Intraknit Thermal Merino Bottom can be worn on their own or below your puffy pants to maximize warmth and ventilation during the colder months of the year.