I have been watching this thread and thought I would chime in because the Icebreaker superfine 140 was mentioned. I bought one of these shirts a few weeks ago. So far I am very happy with it. I have not had the opportunity to do any hiking with it in warm weather because I live in northern Minnesota. I have been wearing almost every day since I got it and I really like it for an every day t-shirt. I am looking forward to trying it in some hot weather this summer. One word of caution the shirt does not have flat seams, they are surged seams. I have not noticed any problems on the few day hikes I have gone on but with a heavy pack the seams might start to chaff.

I am overheating rapidly when hiking, and merino wool (Icebreaker shirt) tends to dry much slower than other fabrics.

The best shirt I have used are running shirts.
Worth mentionning: newline shirts.
I also use adidas shirts, but they are not as effective as other running shirts. I really like the new nike shirts.

For cold weather, I found a Insport running shirt made of powerdy to be the best shirt so far.

I've done well with Duofold and Walmart. And about half of Texas is just ungodly hot and humid. The rest is just ungodly hot and dry, and cotton is king. Well..there is the Panhandle, which can be like Siberia.

The new Capilene is great stuff. It fits great, wicks great, insulates great and also does not reek with odor like the old Capilene did. For hiking in hot, humid weather try the new Capilene 1 (comparable to the old Capilene Silkweight). I have found that the Capilene 1 wicks great and keeps me feeling cool and refreshed while hiking in hot, humid weather and it drys extrememly fast after I stop exerting myself. It drys so fast that it seems to occur in only a matter of minutes. The sizing of the new Capilene is also much improved over the old Capilene. I wore medium in the old Capilene but I wear small in the new Capilene and the fit is better. I tried Merino wool but find that it gets wet,stays wet, takes forever to dry, does not keep me feeling cool and refreshed in hot and humid weather and is a huge pain in the rear to wash and dry. Bottom line for hot, humid weather: Capilene 1 GOOD, Merino wool microweight BAD.

I'll give another vote to Duofold, which I find to be lighter and dry faster than anything else I've tried. Capilene is greatly overrated from my experience on the wicking, drying, comfort and stink dimensions. I've tried the superfine and slightly heavier wool shirts, but I hate the way they smell when wet and they seem to take a lot longer to dry.

I love Mountain Hardwear Wicked tee. Sort or long sleeves.

For $8 - $12 a shirt, I thought it was a good deal and worked great this weekend in the Trinity Alps.

I agree with Francois, that merino wool takes a long time to dry relative to synthetic fibers. I just returned from a trek to Everest Base camp (March) and I was so excited to have my icebreaker merino wool shirts with me, because I knew that they wouldn't smell for the 5 days I would wear each of them (and they truly remained odor-free). But even though the temperature was often in the 40s-50s during the day, I would inevitably get a sweaty lower back from carrying my backpack, and the shirt would take forever to dry despite the dryness of the air in the Himalayas. So even though I love merino wool for its feel and insulation, I do not think it is accurate to say that it is a good moisture-wicking material.(I had the icebreaker 200 long sleeved tee and 150 short sleeved tee).

I also agree with all the posts about capilene being stinky...so now will be looking for yet another hiking shirt.

Edited by sobe00 on 04/07/2011 04:02:01 MDT.

Personally, I find it hard to hike all day in the hot summer with even the thinnest of wool shirts. I wear synthetic during the day (the thinner the better, for ventilation), and usually bring a long sleeve merino shirt for the evenings. My favorite hiking shirt is an old adidas sleeveless that was thin to begin with and even thinner after to about 6 years of wear.

I'll add a +1 for wool as the best of all worlds. Some weather conditions -- very hot and very humid -- are more comfortable in some synthetics, but in my experience, the smell factor overrides the extra comfort.

Thin wool -- 140/150g fabrics -- does very well. I've spent time in Texas and Hawaii, among other places, and done well in this in a broad range of temps.

In a perfect world, I'd recommend the Icebreaker Polos -- Detour Polo is my favorite. Weighs 6.3oz in a medium, looks great out on the town and is comfy hiking in almost any temps. Expensive, though. I justified getting a pair of Icebreaker polos before my honeymoon to Hawaii last fall. Figured it made packing easy... two shirts that I wore 90% of the time there, and I could go from an 8-mile day hike to dinner at a fancy restaurant without changing shirts.

If all you want to do is athletic activities and be comfortable in the summer, then I'd recommend cacona synthetics -- I've found them to have the best odor/comfort ratio of any of the synthetic fabrics. But when packing for a trip, they come in as runner-up to a good wool shirt.

Rail Riders Men's Eco-Speed-T. This is what I use in the desert once my summer tan is obtained.

It is a mesh-like material.

as others have said ... whatever runners use ... theres no way youll sweat more than them in a normal hike

i prefer nike dri fit myself ... you can get cheap running stretch shirts at wallymart/target, etc ...

one thing no one has mentioned ... size it TIGHT

the more skin tight it is ... the better it wicks ... loosey goosey shirts only hinder wicking

im never afraid to show off my ginourmous belly in the name of performance

Been wearing them for 10 years or so (not continuously - I've taken them off occasionally for washing) and although some of them do pill the price can be very right. I bought a few for my wife recently at like $6 each.
Have fun,
Steve

My two favorites:

1) Mountain Hardwear Super Wicked Shirt (has zip and collar for sun)

2) Patagonia SS Puckerwear shirt (outstanding in the heat 65/35 poly/cotton blend)

> but it is lighter than the lightest merino that i've ever seen.

Capilene 2 and 3 are not particularly light. You can find wool garments that weigh the same as Capilene 1 garments.

+1 on the Walmart moisture wicking tees (brand is Starter DriStar). They're dirt cheap, light (4.7 ounces for a 2XL), and they wick moisture at least as well my (much more expensive) Brooks technical (running) shirts. Also, the material has a pretty good hand to it.