Rock America Non-Music T-Shirts are highest quality, officially licensed t-shirts. Most of our pop culture t-shirts are 100% cotton and preshrunk for a quality fit. They’ll hold up to the toughest mosh pit! We have the latest designs and logos on our t-shirts, as well as t-shirts in classic designs that have stood the test of time. Thor "Mighty Thor" T-shirt. Official short sleeve Thor T-shirt.