Looking for a pair of light (despite their name) long underwear that will keep you warm throughout the coldest months, but versatile enough to rock the rest of the year? The Patagonia Capilene Midweight Bottoms breaks the mold of traditional synthetic-norms, winning over several testers and nearly snagging our Best Buy Award. This thoughtfully designed pair offers a lofted-warmth that puts it on par with full-Merino competitors, an airy fit for top-notch breathability, and soft-sided coziness that is perfect for lounging around the house. Feel just as comfortable sliding these on before diving into snowy backcountry ski terrain, or packing them for a bit of extra warmth on fall backpacks. Barring some inherent durability issues that come with lighter-weight fabrics, these bottoms came very close to taking the top spot in our review.
Patagonia Capilene Midweight Bottoms Review
Compare prices at 3 resellers Pros: 100% recycled polyester, light fabric weight, impressive loft and warmth
Cons: Questionable durability, saggy bottom
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Our Analysis and Test Results
We are impressed with the newest rendition of the classic Capilene Midweight Bottoms. These bottoms sport one of the lightest material weights in our review, but through a diamond-grid knit pattern reminiscent of Patagonia's celebrated gridded fleece, it offers a warmth-factor far superior to their weight. Not only that, but the 100% recycled polyester is soft to the touch, and does a great job of wicking away moisture when the going gets tough. Don't expect to get too rough with this layer, however. The thin synthetic fabric has its drawbacks in terms of durability.
The Capilene Midweight bottoms are an anomaly when it comes to the general rules for weight-to-warmth ratio. Knit with a 100% recycled polyester, these bottoms tip the scales at a mere 147 g/m² — the lightest fabric weight of any pair in our review. When we first pulled these out of the box, we thought we had accidentally ordered their lightweight Capilene option. These bottoms perform way above their weight, and truly offer the level of warmth we expect out of midweight base layers, which are generally constructed out of fabric weighing at least 200 g/m².
The secret to the improbable warmth of this layer is the knitting pattern. Warmth of a layer isn't generated from the fabric itself — it comes from the heat generated by our bodies, and that heat gets trapped in the warm air bubble created by material loft. To mimic the thermo-trapping capabilities of natural fibers like Merino wool — a fabric that is coveted for its loft-quality — the recycled polyester of the Capilene Midweight is knit in a special diamond-grid pattern. This creates little loft pockets that do a particularly good job of capturing the heat rising off our bodies.
For a pair of long underwear marketed as midweight, the Capilene Midweight bottoms sure seem confused when it comes to the normal standards of that definition. Rather than succumbing to the peer-pressure of their category, these are constructed of a thin fabric weight — and this quality proves particularly effective when it comes to increased breathability.
We were surprised to discover, through numerous trail runs, that these do in-fact perform like a pair of lightweight long underwear. Whether it's the relaxed fit that allows room for airflow, or the hollow-core polyester that makes quick work of any sweat, these bottoms simply out-perform their listed weight class when it comes to breathability. Then factor in the odor-eating HeiQ Fresh odor control, and say goodbye to the traditional pitfalls of the full-synthetic base layer.
Comfort and Fit
While a 100% Merino wool knit has, for a long time, been the gold standard in terms of plush comfort, polyester made with 100% recycled content seems to be giving it a run for its money.
The Capilene Midweight bottoms are extraordinarily comfortable for a full-synthetic, that often are itchy when worn next-to-skin. Even the waistband is soft! The gridded pattern of the inside has a similar feel to a gridded, lofted fleece, and the face fabric has the smooth feel of brushed nylon, making these very easy to layer over.
One thing we really appreciated about this pair of long underwear is the relaxed fit — imagine a pair of sweatpants, slightly tailored for athletics. Many other bottoms are designed with a skin-hugging cut that sometimes leaves us wondering if we resemble one of Robin Hood's Merry Men-in-tights. The ample legroom — particularly through the knees — gusseted crotch, and flatlock seams only add to the existing stretch of the material, providing unparalleled freedom of movement.
The airy fit of the Capilene Midweight bottoms does leave the buttocks hanging a little saggy, but we didn't find this to interfere much with the fit when it comes to layering. Not necessarily form-flattering running tights, this layer is best suited under a pair of snow pants, or for simply hanging around the cabin.
These bottoms do raise some eyebrows when it comes to durability. After short-term, albeit extensive use, the Capilene Midweight is one of the few pairs of long underwear to show signs of wear on their exterior. Almost too quickly, the face fabric of these bottoms began to pill. These findings were supported in the lab, where the outside of this layer was visibly worn after our abrasion test.
Despite the appearance of a hole forming as the result of this aggressive test process, remarkably, the interior fabric seemed to be unharmed. While these bottoms may show signs of wear-and-tear on the outside, on the inside — where it counts in terms of breathability, warmth, and comfort — this pair of long underwear appears almost as new as the day we pulled it out of the packaging.
With a level of comfort and function on-par with many of the full merino wool base layers we tested, the Capilene Midweight bottoms are a pearl amongst a sea of synthetics. With thoughtful additions — like the HeiQ Fresh odor control, and the diamond-grid knit — to make up for the areas where synthetics normally cannot compete with their all-natural counterparts, you can grab a layer with comparable performance for less money. If it comes down to the question of ethics and sustainability, you can feel good knowing that this pair of long underwear is made of 100% recycled content and is sewn according to Fair Trade standards.
The Patagonia Capilene Midweight Bottoms are helping shift what we think is possible in terms of both garment technology and production. Considering that you can achieve near Merino-quality performance with a full-polyester layer is impressive in itself. Then consider the fact that this polyester is made of 100% recycled content, and we have entered the realm of groundbreaking.
— Aaron Rice