These t-shirts are probably the best shirt I have found to wear as an undershirt. They are thin enough to not add hardly any bulk underneath any shirt I wear. And because of the material, and proabably the way it woven or whatever, they are very cool. Any amount of wind goes right through, which is great for undershirts. And they dry really fast, you can easily hand wash them anywhere and wring it out and hand it up and it will be dry at least overnight easily I'd not a couple hours. Bottom line, best undershirts out there.