I recently used the crew long sleeve in a layering system in combination with the mid-weight zip T and this two part system. This layering system kept me warm in the cold Arizona mornings yet I was able to remove layers when the weather would warm. Awesome piece and sizing was perfect.

In one of the previous reviews it is said that this product cause led them to itch. And I’ve found a little bit of the same issue. The seams are sewed so thick it feels like it’s sewn together with fishing line, it’s is very durable but can cause some irritation in the skin if you have sensitive skin. I just recently purchased this product and I have not used it in the field yet but I would like to see this product with a softer seam for those product that are going to be a next to skin layer. It is super light weight and it is comfortable other than the seams. But just sitting down wearing it for the first 15 minutes out of the box felt a little scratch maybe I’ll get used to it and won’t be so bad anymore. Well see.

Love this shirt. Fit is perfect. Have worn this as an outer layer for warmer weather hunts and as a base and insulating layer for 4th season Rocky Mountain elk hunts. I only wish that Sitka would make one of these in blaze orange.

This shirt is great it is very light and comfortable but does easily rip on branches and brush.

Have worn this shirt by itself and as a layer and absolutely love it.

Absolutely love this shirt so far. Breathable enough for those hot afternoon early season hunts, and I've even used it on some dove hunts. Can't wait to see how it performs as a very base layer in the later season

Physically the lightest weight shirt I've ever experienced!

I use these tops for flyfishing for trout and the pattern matches perfectly to the terrain I fish in. Bodyline is not accentuated with these tops and I am able to get closer to my target fish because of it .A really awesome product for Australia and NZ streams.

Awesome piece of gear as a base layer or outerwear in the warmer months. I only wish it was offered in black too for hunting out of a ground blind!

I wear this top when flyfishing in alpine environments and find it to be a real winner in disguising the upper human profile. Its well made, comfortable and the concealment factor is far beyond any other product I have tried. 10 out of 10 Sitka.

I live on the Georgia/Florida line and too often the temperatures are in the 90s during early season. This winter (2017) has been one of the hottest. With temperatures fluctuating from 50s to 70s (and occasionally 80s) it's beneficial to have a clothing layer that doesn't cause you to overheat and sweat. This LS shirt is cooler than my Under Armour PT shirts, wicks away moisture better, and the dry time is unbelievable. I was skeptical about Sitka Gear (due to the price) but now I foresee myself gravitating to this company. I have a few pieces of Sitka Gear and EVERY arrival of clothing is comfortable AND the fabric/sewing is immaculate.

The quality is not as good as the older Core products. Also the "tail" is a bit awkward. PLEASE bring back the Core Zip-T!!!

I bought this as part of my early season whitetail system for archery hunting in Central Texas. Temperatures can still soar into the high 90s here in mid and even late October. Bottom line: this new version of the Core Lightweight is a dramatic improvement on the already incredible first series. It seemed to coax the cool out of the faintest south breeze and dried unbelievably quick. A small investment toward early season comfort.

This is exactly the shirt I needed when early season scouting in Northern Az. It kept me warm enough in the chilly mornings that I didn't need to add any extra layers, but was lightweight and breathable enough to keep me cool when trekking and traversing terrain. Perfect as a standalone shirt, I use it for early season Coyote hunting as well. Now, with the temps dropping, I will have to look into the Merino shirts, or potentially a jacket/vest. Overall, fantastic shirt. thumb gaiter is a nice tough as well when used with gloves.

Wearing this for the first time this whitetail season here in Maryland. Pretty decent on coolness with temps in the 80s and high humidity. It isn't like out West. We NEVER have a dry heat. Took a doe at 21 yards yesterday and she never saw me even though she looked right in my direction. Because she went down and crashed in the Phragmites, I decided to climb down early and trail her during good light. Upon coming to the impact area, I looked left and the 4 other does with her were looking right in my direction 43 yards away. On public ground, this normally would have been sayonara. They allowed me plenty of time to nock, aim, shoot, and harvest one of them. The blob effect of other patterns would never have allowed me this much time and movement. I know this all too well from past experiences. It'll be a hard sell to tell me that Optifade doesn't work. 2 does with one from the open ground is rock solid in our woods. I'm liking this shirt already.

Excited to receive the lightweight underlayer because of the reviews as to its properties. However, ordering the XL size, I found the sleeves too short. Other items I have ordered from Sitka in XL have sufficient sleeve length but this item did not. The size chart for XL indicates sleeve length is 35.5" but I found this item did not reach to my wrist bone. I measured the sleeve from the middle of the back of the neck to the end of the sleeve and it measured 33.5". Allowing for some stretch,I would say the sleeves are actually only 34". Perhaps, one should order one size larger but the body was already slightly large for me so I had to return to Sitka. Nothing wrong with the item other than size is not as indicated.

Was caught up in the scentblocker game for years until I started researching carbon and its flaws. I hunted over 30 days this year using this base layer and it was awesome. Great moisture wicking and the science of polygiene gives the perfect 1-2 punch.

First, let me say that I have enough Sitka gear to be labeled a fanboy for sure. Having said that, this is by far the most disappointment I've had with a Sitka product. This shirt made me itch so bad I had to take it off after wearing it only an hour. It seriously felt like the very old style of wool we all wore before merino was all the rage. It's like someone sprinkled a bunch of fiberglass insulation under the shirt before I put it on. And Im far from the allergic skin sensitive type. It's too bad, because otherwise I really liked the way it felt in the hand, the way it was constructed, and the way it fit. Little things like loops on the thumbs to help keep it from sliding up while layering were a nice touch. Lastly, as others have said, I'm sure it would dry really fast once wet. The latter is the reason I purchased it to begin with. In most situations I prefer to wear wool, but in wet situations (i.e. Prince of Wales Island, Kodiak island, etc.) I would prefer to wear synthetics because they dry faster (and are lighter when wet and lighter in general). But this was so uncomfortable I would live in soaking wet merino for a week rather than be in this for one day. (This is my first negative review… I hope Sitka actually publishes this. If you are reading this, consider it a testament to the integrity of the company.)

Absolutely love this shirt and all of the updated 2015 core series. I would quite literally take 1 of these shirts over the old core zip t, and I have also found that I opt for this shirt over any of my merino wool on just about any occasion. I've been easily able to get away with one shirt for a weeks worth of backpack hunting and not have issues with the shirt stinking or feeling excessively stiff or dirty. It also dries far faster than wool or any other synthetic I've had. Needless to say, I'm sold on this shirt. Plus as a gram counter the weight is a true upside to this piece as well.

Love this shirt! I wore this shirt on an Idaho elk hunting trip. Between rain and sweat I was wet a lot, but the shirt dried really fast and I was able to wear it multiple days.