For summer use in the Sierra Nevada, I normally use a poly t-shirt with an extremely thin long-sleeve shirt over it for sun protection. Then, the first warm layer I use (currently) is a Sportif 100-weight microfleece long-sleeve shirt. It is soft, durable, and somewhat warm, with a button-up front and two front pockets. The only problem is that it weighs about 11 ounces in a mens small size. I'd like to replace it with something equally useful but perhaps a bit lighter. I've looked at what I see in the marketplace, and I don't see anything better, or at least not lighter.
I have several good wool shirts and sweaters, and they are too heavy. I have some medium fleece shirts, but they are only a quarter or half zip. I have a good windshirt, but it is only half zip. Pullover shirts are not my favorite.
If I don't find something new, I might have to start hacking away at the old Sportif shirt.
Any suggestions out there in the marketplace?