The best backpack bottoming shirt can absorb sweat and regulate the temperature, providing excellent personal comfort. This is an equipment category that you don’t need to think too much about-although they vary from one piece of clothing, overall, the basic layer is very simple. Nevertheless, we will introduce you to the best materials and other features so that you can find the best backpack base layer.
Smart Wool Merino Wool 250 | The warmest layer Patagonia Capilene Cool Daily | The best lightweight synthetic REI Co-op Lightweight | The most affordable Icebreaker Merino 200 Oasis | The best looking Meriwool lightweight base layer | Best cheap price Merino REI Co-op Silk Long Lingerie | Best Ultra Light
The ability to effectively breathe and wick away sweat, keeping you comfortable and not wet and cold, is one of the most important functions of your bottoming shirt, especially for active bottoming shirts (those that you wear next to your body when hiking). The type of fabric, weight, breathability and fit will determine the breathability/hygroscopicity of your base shirt. Make sure your bottoming shirt is close to your skin (not too tight) to maximize the efficiency of perspiration.
Silk: Silk is the lightest material. It is warm in weight, but not very breathable or durable. May be more suitable for pajamas than sportswear.
Merino wool: Merino wool is particularly soft and keeps warm even when wet. It also has natural deodorant, flame retardant and moisture wicking effects.
Synthetic fibers: Merino wool and silk are both more expensive than synthetic fibers (usually polyester or nylon, sometimes blended with elastic fibers to make them stretchy). Synthetic fiber is durable and breathable and moisture wicking almost as merino wool. However, they do not have the same level of close-fitting comfort and will emit a terrible smell after you wear them for a few days.
The fabrics have different densities/weights, depending on how warm you want them to be. For example, merino wool is usually sold in 100-250 weight varieties, that is, 100-250 grams per square meter (gsm). Merino wool of less than 200 gsm is thinner, lighter and more suitable for warm conditions. Anything higher than 200 gsm is very suitable for cool weather.
Interestingly, 200+ GSM merino wool does not seem to be easily damaged by insects. On more than one occasion, we have put 150 and 250 g/m2 merino wool garments in the same drawer, but only the 150 g/m2 garments were moth-eaten.
Some ultralight enthusiasts will use heavyweight bottoming shirts as their middle layer in warm weather, instead of heavier and bulkier clothing like wool.
Some base layers use thinner materials or more open weaves in hot and sweaty areas such as the armpits and behind the knees to improve breathability.
Merino wool is naturally antibacterial, but some synthetic base layers have antibacterial treatments designed to suppress odors. The deodorant properties are good, but it may not be the deciding factor for most hikers, because the fear of hikers will eventually overwhelm the limited deodorizing ability of any clothing.
Thumb loop: Put the sleeve on the wrist and cover part of the hand-very suitable for cold environments.
Pocket: One or two small pockets, or a kangaroo pocket, you can store small items or warm your hands.
Zipper: The top quarter of the zipper provides you with more temperature control, because you can open the zipper as needed to dissipate heat.
Winter: When hiking, please wear thicker (200+ gsm) leggings and long-sleeved round neck or quarter zip top. Choose something elastic that can fit tightly to your skin without restricting exercise. If it is breathable/moisture wicking, add points. At this time of the year, you might wear a woolen sweater and a set of rain, wind, or hiking pants over your base shirt to increase warmth. When you reach the camp, put on a second set of dry thick base layer (still 200+ gsm). These should still be close to your skin to maximize warmth, but breathability and fluidity are not as important as you are just sleeping on them.
Spring and Autumn: Put on the base layer of your activity (flexible, breathable) as the outer layer. Whether it is a thin layer or a thick layer depends on the path you want to hike and whether you are running hot or cold. Once again, bring a pair of dry, thick foundations to sleep because it will still be cold at night.
Summer: Lightweight, breathable shirts and shorts (or hiking pants) are suitable for most hikers. If you want special pajamas, ultra-light silk bottoming shirts are excellent backpack pajamas.
No. Technical, high-performance hiking bottoming shirts can become very expensive-think about $50-100 or more for a single piece of clothing. But you can find a cheap, lightweight synthetic base layer in the Active Wear section of any large store or even thrift store. There is a performance difference between cheap sportswear and expensive mountaineering clothing, but it is sometimes exaggerated. In addition, after months of tracking, no matter the cost, your clothes will turn into stinky tattered rags.
To maintain internal consistency, all specifications listed are for men's medium size unless otherwise stated. For the same reason, we focus on long-sleeved round neck tops, but all of the bottoming shirts listed are also available as bottoms, and many also offer hoodies, half-zip or short-sleeved T-shirts. As we said above, if the budget is limited, you can use any pair of synthetic trousers from thrift stores or hypermarkets as leggings. However, we have carefully selected this list for products with excellent breathability, durability and/or comfort.
The best backpack base layer: Smartwool Merino 250.
In addition to having stunning colors and patterns, Smartwool's tightly interlocking knit 100% merino wool structure makes it an incredibly warm and soft base shirt. It is very breathable, has a natural odor suppression function, and has frictionless flat-lock seams and ribbed elbows for maximum mobility.
If you want a lighter and thinner bottom layer, please check out the Smartwool 150 series. You can also find Smartwool leggings, half-zip tops and T-shirts.
The best backpack foundation: Patagonia Capilene Cool Daily.
The elastic UPF-50+ fabric keeps you cool and protected in hot weather. The Patagonia Capilene Cool Daily series is perfect for hiking in sunny summer: it is very comfortable, instantly dries, keeps chafing seams to a minimum, and even has Polygiene odor treatment to help counteract the sweat that polyester usually produces The stench is notorious. Patagonia strives to achieve sustainability in its product line, and their Capilene base layer is no exception. For example, this shirt uses 50% recycled polyester fiber and has obtained fair trade certification that demonstrates labor ethics.
Read our review of the Patagonia Capilene Cool Daily Hoodie.
Best backpack base layer: REI lightweight base layer.
REI’s synthetic base layer is suitable as a sportswear, with UPF 50+ sun protection and various comfort and mobility enhancement functions. These include raglan sleeves, underarms with gussets, four-way elasticity and flat seams to minimize chafing. It is looser than many base layers, which may reduce its breathability and moisture wicking properties.
You can also purchase REI’s Lightweight Base Layer short-sleeved T-shirts, half-zip tops and leggings. Or, if you want thicker and warmer layers, check out the REI Co-op Midweight Base Layer series.
The best backpack base layer: Icebreaker Merino 200 Oasis.
Icebreaker and Smartwool bottoming shirts are comparable in most aspects, but if you like a more slim and sporty style, Icebreaker is your best choice. It also has a tail hem (more coverage of the hips), which increases warmth and reduces the risk of the shirt rolling under the backpack. For these two reasons, we believe that this Icebreaker product is a better active layer than Smartwools. Merino 200 Oasis also has gusseted underarms, flat lock seams and offset shoulder seams to reduce wear on the backpack straps. The 200-pound merino wool is lighter and more breathable than Smartwool's 250. Likewise, it is ideal if you are looking for warmth in between.
Icebreaker's Merino 200 Oasis collection also includes leggings, short-sleeved T-shirts and half zippers.
Hikers like to compliment Merino wool-warmth, moisture-wicking, breathable, deodorant-but unfortunately, thrift is usually not among the many magical qualities of yarn. For many hikers, the extreme cost of merino wool is a huge obstacle. Enter Meriwool, which is a 100% merino wool bottom production line, and its cost is about half that of most competitors. Their lightweight (180 weight) bottoming shirt is the cheapest option, and still uses thoughtful designs such as raglan sleeves and various sizes.
Best backpack leggings: REI Silk Long Underwear.
REI's silk trousers feel great to fit the skin and are very warm against such a thin transparent layer. You can wear them under hiking clothes to increase warmth, but they are not very breathable or durable, so we recommend using them as luxurious camping pajamas. Can also be used at the bottom.
Of course, because we are very smart! It's also very attractive (not to mention extremely humble).
However, if this is not enough to impress you, then there is also the fact that everyone who contributes to this article is an experienced trekking hiker who has already traveled thousands of miles. We are equipment fans and like to test our equipment on trails of different lengths, and in pursuit of a more comfortable day in the wild, we have tested dozens of base layers.
In addition, we will do our best to understand the equipment preferences of the forest road community (we are definitely the nasty people on the forest road who always want to know what other people are packing). This means that our choice of the best backpackers is not just our opinion: they are based on feedback from the hiking community over many years.
The embodiment of ability and backpacking ability.
Featured image: Graphic design by Chris Helm (@chris.helm).
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