in between slim and relaxed, its not super loose but tends toward boxy. I take a small in american app apparel generally and the OL slim tee (at least from fall) is more boxy, but still fits great. (with a wash and dry). Sizing down causes weirded because of the sleeves IMO so I say go true to your normal t-shirt size and if its a bit too big don't hesitate to wash it on gentle cycle and dry it low. I was thinking of getting some of the spring tees too.