Testing these base layers in real-world situations, as well as specific tests conducted in our lab, are what allow us to provide you with such in-depth reviews. From being dragged up chimneys on desert towers to skinning up volcanoes in the Pacific Northwest, we run these tops through the gauntlet. Below is how we test for each metric.
This one is simple. We wear them in really cold conditions. Alone and part of a layered system, we see how efficient they are at keeping us warm when temps drop into uncomfortable ranges.
We use a combination of real-life experience as well as a regulated test within the lab for this metric. We skinned up Mt. Hood, hiked steep talus cones to climb desert towers, pedaled steep mountain biking trails, and ran winding mountain trails in Colorado. In the lab, we tested each top, one at a time in a temperature-controlled, indoor environment. We worked up a sweat with the same short but rigorous exercise routine while wearing each base layer. We then timed how long it took for our skin and the inside of our shirts to dry after stopping.
Comfort & Fit
We wore them a lot, and with an extremely critical eye. We looked at the comfort of the fabric of each layer next to the skin. We compared the way they fit on testers of different body types, looked at the stitching patterns and features that allow them to move with us and keep from exposing our bellies and backs. The length of the torso and arms were recorded, how comfortable the neck hem was, and the stretchiness of fabric as well as specific features like a drop-tail hem, tapered arms, and thumb loops. We critiqued how they formed to the body, if they bunched up or were uncomfortable in any way while being active, and observed if they were itchy at all, especially when working up a sweat. Through heavy use, a few climbed their way to the top of the comfy list as testers found themselves wanting to wear them all the time.
This was another combo of observation while wearing and playing in them as well as a controlled test in the lab. We beat the heck out of these things- dragging them up desert towers, scraping through slot canyons, and bushwacking into the night. We tested to see how they held up in all of these conditions. We also sent them through wash and dry cycles to see how they held up in what tends to be the environment that breaks base layers down the fastest.
For our lab test, we took a section of the fabric at the elbow and vigorously drug it back and forth against a 1-foot piece of rough and textured granite to see how the fabric held up to abrasion. This test very clearly gave us an idea of what fabrics would stand up to abrasion over time and which ones were simply not built for it.
As we've expressed before, the time a base layer takes to dry while next-to-skin and the time it takes to dry away from a body are significantly different. To the base layer's ability to do both, we recorded and noted each tops ability to dry while we wore them especially during our testing for breathability - working up a sweat in high-energy activities like mountain biking on warm fall days, climbing in the desert sun, and skinning in not the coldest conditions.
To test the dry time of the fabric completely saturated and laid, we soaked them thru and laid them all out at the same time to dry. Checking them and recording the time it took them to feel dry on the surface as well as dry completely. The significance of this test wasn't necessarily in the specific times it took them to dry but how they dried compared with one another.
We incorporated each top into any and every layer combination we could imagine. We observed how they felt against the skin with layers of different types and fits over the top of them, layered over top of t-shirts and other base layers. We layered tight and sticky technical fleece mid layers, wool sweaters, slick nylon down jackets, and tacky synthetic insulating layers like the Patagonia Nano Air or R1. Any combo we could think of, we tried. We observed if the sleeves bunched up, if they felt bulky or restrictive at all, if they were itchy, if they fit tight or uncomfortable, and how much static electricity they built up.
By putting each base layer through extensive and exhaustive testing and observation across these metrics, we rated them all for each metric to aid in bringing you the most detailed and helpful review out there.