These A-shirts are made from 100% cotton. The material is breathable and comfortable for everyday use. The hems are longer, so they stay tucked. The neck and armholes are banded for durability and maximum comfort. Expect moderate shrinkage with the first wash. Sizes runs small. General sizing guide corresponding to US size is: Small (29-32), Medium (32-35), Large (35-38), X-Large (38-41), 2 X-Large (41-44). Machine wash, tumble dry low.