Great length for working in, without showing off the six pack I don’t have, whenever I reach for something over my head. Also helps if you want to work with your shirt tucked into your pants, it doesn’t feel like it’s constantly pulling up, and that you’ll have to readjust it, every 5 minutes. Material breathes without feeling like I’m wearing a shirt made of paper. And has a good shoulder width, so when you pick up something you don’t have worry that you’re going rip the fabric apart like the hulk. It’s quick drying too if you work around water.
6’ 200 lbs: bought a large, it’s a good size.
Wish that they had more color options, and maybe a small pocket for a pen/pencil on the sleeve.

I'm 6'2" and ~200 lbs. I opted to go XL. Probably could have gone down a size but I prefer looser.
It's pretty long in the waist. It seems like the lowest button is meant to be left open if desired.
Top button can be left open without invoking the awkward V neck look (shirt kind of holds its shape to close the neck). Buttoning the top button doesn't choke though.
Fabric is light and thin but feels durable.
Liked it enough to buy another. Would be nice if they had more colors beyond blue and charcoal.

Great shirt, sizing and fit is spot on with their other items. Wish they had more colors though

I think the shirt is fantastic. I admire the fabric, cut and all aspects of the design. I don’t have a lot of the 1620 stuff outside of a hoodie and the some NYCO pants, all of that which are everyday staples, but judging from those items I can see how someone might not like the short sleeve button up. I however live in GA, hot and humid, and that shirt is great. For cold (hahaha) weather I just wear it over a thermal and am good to go 90% of the time. Look, I ain’t gonna lie, the price tag for 1620 is almost undoable for me. But the clothes are so good and the cause so worthwhile, I just wait for a chance (tax check, job bonus, extra hours for a while, patina collection), save, and get what I can. Don’t need but a couple pair, a shirt and a hoodie, and all that will last a long long time. So please don’t dumb it down, cut cost or anything else. It won’t be the same. It wouldn't be 1620.