Review on 👕 Icebreaker Merino Men's Anatomica Long Sleeve Crew Neck Shirt: Slim Fit Undershirt in Merino Wool - Ultimate Comfort and Style by Todd Cowdrey

These shirts are great, just keep in mind that the Icebreaker animation is pretty tight (more than tight but not compressive). This is a size to wear as a first layer. So if you even wear them over a t-shirt, I would go one size up from your usual non-icebreaker size. It's perfect for keeping in your bag before a flight or when the nights start to get a little chilly. Very thin so not very warm but very soft and comfortable. Like all merino fabrics, it has good odor resistance so you can wear it for several days when you're on the go and want to take a light backpack with you.