Outdoor Research Echo L/S Zip Tee

Thinnest, lightest, most breathable long sleeve shirt. Deep zip adds a lot to usability. Bit fragile.

Thin Grid:

I live in Japan, where the humidity adds a lot of warmth in the summers, and cold in the winters. Trekking in the summers can be grueling — and I'm always on the lookout for very thin shirts that breathe well. 

Two of my favourite shirts are the Montura Run Zip Maglia l/s, a strong runner shirt with more spandex (less quick drying), and OR's Echo Zip l/s. 

The OR Echo Zip shirt is very very, very breathable. It is the thinnest, softest shirt I've ever seen. Significantly more so than for example a Patagonia Capilene 1 shirt. OR used to have very thin summer weight Polartec PowerDry shirts, but again, this is significantly thinner and less clammy feeling.

The Echo's AirVent fabric has taken cues from grid pattern fleeces it seems. If you hold the fabric up to the light, you can see a grid pattern like you commonly find in PowerDry fleeces and shirts, only now at ultra light weight. 

Usage:

This is the least clammy shirt I know of. It is great in intense heat, or really humid environments. In general when at higher elevations, I feel this shirt is best used as a base layer. While other shirts work great by themselves, this one for me works best in combination with a windshirt, or thin windshirt vest (windvest?) over it. Because the fabric is so thin and has such an open weave, you do get flash drying chills when you hit a peak or ridge with cold wind exposure. On lower elevations this is not a problem of course.

When layering, the huge front zip (about as long as my forearm) helps a lot. I like to open the zip up, while having my chest and neck covered by my zipped up thin windshirt vest. 

I love long sleeves. I need the sun and bug protection they provide. Normally if I need to I will vent a bit by exposing my forearms every now and then, but to be honest with the Echo I hardly ever bother. There are versions with and without the zipper, and with and without long sleeves. For me the tiny extra weight is worth it. 

Weight:

A Medium long sleeve with zipper weighs in at 111 gr. (3.9 oz). (Yes, that kind of deserves its own paragraph.)

Fit: 

I'm 184cm (6.1) and about 72Kg (159#). I'm often in between sizes with my shoulders needing a Large, the rest of my body needing the Medium. This shirt is no exception. 

Drawbacks:

Perhaps inherent because of the thin fabric, this shirt snags a bit more easy. It is thin. It is a grid. I haven't used this shirt for a whole season yet, but, I can imagine I would need a replacement sooner than with other shirts. You have to decide if that is worth it to you. If you do a lot of scrambling over rocks I don't know if this is the shirt you'd want.

Also, you might want to think about the colour - my shirt is blue and I don't have this problem but I read about people being a bit self conscious when wearing the white version and having their nipples come and say "hi!". 

I would like it if the shirt gave more sun protection (the Echo is 15 UPF which is common for thinner/thinnest base layers from different brands), but I'm not sure it is possible for a fabric with these qualities. 

Overall: 

It is hard to convey how much of a difference this shirt makes my training and trekking in the summer. All I can say is if you are looking for the thinnest, most breathable, least clammy feeling, lightest weight base layer shirt — then look no further.

I do feel it is almost a bit of a speciality item in this sense though. If you are looking for more protection, like a shirt you wear by itself when running or hiking at higher altitude, you might be better off with a more tight weave item.