I've always worn a long-sleeve base layer t-shirt for all my hikes. It's somewhere around 4-5 oz. It works except for 2 things: since it's very thin and sticks to the skin, mosquitos bite right through it; and it looks pretty terrible. I know that looks don't matter, and i never give it a 2nd thought on my own. But my wife is going to be doing more long trails with me this year and next, and she thinks i look like hell wearing basically this undershirt.
While thru-hiking the PCT i saw most everyone wearing sharp long-sleeve button-down shirts like probably by Ex-Officio or something. I've been looking up shirts like this, but i can't find anything that comes in at under 7 oz. I'm not willing to add weight to what i'm used to, but i'm wondering if anyone can recommend a shirt like that that falls into the 4-5 oz. range.