Durable 100% cotton. Binding at the collar helps the neckline keep its shape. The Uniqlo U collection is the realization of a dedicated and skilled team of international designers based at our Paris Research and Development Center led by Artistic Director Christophe Lemaire. - Heavyweight 100% cotton jersey fabric. - Durable dry touch, heavyweight jersey fabric gains character with every wash. - Binding at the collar helps the neckline keep its shape. - Relaxed, unisex cut. - Neckline inspired by vintage military T-shirt designs. I have only worn this once (I promise this is true) and washed it so the next person will love this top.