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  • Merino wool helps maintain comfort whether the climate is warm, cold or in-between
  • UPF 50+ fabric provides excellent protection against harmful ultraviolet rays
  • Shoulder panels eliminate top shoulder seams, reduce chafing and optimize comfort under pack straps
  • Rear body seams wrap around to front to enhance fit, and sculpted side panels also enhance fit
  • Flatlock stitching eliminates abrasion, increases comfort and enhances fit by reducing bulky seams
  • Merino wool does not itch and will not shrink; machine wash and dry


View all Smartwool Women's Long Underwear Tops

REI membership


Best Use Multisport
Shirt Style Crew
Fabric Merino wool
Sun-Protective Fabric Yes
UPF Rating 50
Moisture Wicking Yes
Underwear Weight Midweight
Sleeve Length Long Sleeve
Gender Women's

Size chart

Rated 5 out of 5 by from Love Smart Wool products Love the mid-weight base layers from Smart Wool. I wore them in extreme cold temps both downhill skiing & running & I was very comfortable. It was my base layer with a wool sweater & ski jacket for skiing. Both the top & bottom washed & dried well without shrinking or fading. The blue color is very vibrant. My husband has them in black & it seems to collect lint, but it doesn't show on the blue. Keep up the good work Smart Wool. I'm a fan. (They also make running socks that are very comfortable all year round.)
Date published: 2013-01-17
Rated 5 out of 5 by from Perfect base layer I bought this SmartWool long-sleeved top (in the pale gray) about a week ago, and I have worn it as a base layer under shirts, sweaters, and vests every day since. I am one of these women who's always cold, even indoors, so I put this top on in the morning and keep it on all day. I have sensitive skin, so I was happy to discover that this top, although it's 100% wool, is not the least bit scratchy. The only thing that bothered my skin the first day I wore it was the tag sewn into the bottom seam. So I took my seam-ripper and removed the tag--problem solved! I bought the XSmall in this top, and it's a perfect fit for me. I am 5' 5" and weigh 110, so I'm slender (and not busty). But I usually wear a Small in shirts and tops, so I tried that size on first. The Small in this top was definitely too big for me: the sleeves were way too long, and it was just too big overall. The XSmall, however, was exactly right, as if it had been made for me personally. I highly recommend this top as a base layer. And it's also good-looking enough (it's not see-through and doesn't look like underwear) to be worn by itself. I even bought a second one that I wear to bed. I paid full price for both my SmartWool tops, but they are well worth it! Wish I'd discovered this product sooner. I highly recommend it, especially if you're going to be outdoors a lot in cold weather or if, like me, you struggle to stay warm the minute the mercury drops below 50 degrees.
Date published: 2015-11-17
Rated 5 out of 5 by from Super comfy This shirt feels amazing against your skin. It has a wide (about 1.5") band on the bottom which makes it really... Well, hearty. Amazing product. One small FYI, SmartWool clothes tend to run a bit small. I had to go up a size. (Please don't let this fact discourage you from getting this shirt or shirts like it.)
Date published: 2014-01-23
Rated 5 out of 5 by from So comfortable I used this for 6 days in the backcountry on Mt Baker and it was amazing. Baker is very cold and very wet and even when i was wet, the top kept me warm. I highly recommend it for a midweight top.
Date published: 2013-05-20
Rated 5 out of 5 by from Super warm and comfortable I wore these (top and bottom) when I hiked Mt. Kilimanjaro and I was warm and comfortable the entire summit night in freezing temps. I would highly recommend.
Date published: 2015-01-07
Rated 5 out of 5 by from A Much Needed Layer You get what y ou pay for as the saying goes. This top did the job and is a great value for the price. There is nothing worse than being cold in when you are out in the elements camping night after night. This top kept me warm and the soft material felt cozy without adding extra bulk. A perfect extra layer when hiking in the cold.
Date published: 2016-06-30
Rated 5 out of 5 by from Perfect layering piece! I ordered this top and the matching leggings for a recent ski weekend in Utah. It is the perfect layering piece - breathable, well-fitting, and insulating. I'll continue to wear it by itself and as a warm layer all winter long. This top was pricy, but I expect I'll get a lot of excellent use out of it.
Date published: 2012-12-20
Rated 5 out of 5 by from dont head out without it! Invaluable while sailing up to the pacific north coast, wearing as a layer and looking like a nice sweater when top layers were removed .... nice fit under or over other layers.
Date published: 2013-10-17
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