Very airy and light cotton. The only problem for me is that the neck is a bit large (it's a Small already), so I will have to fix that, but it's a great sundress and I love the texture, feel and the lovely blues.
The picture doesn't do this justice. It is so beautiful and comfortable to wear. It has pockets too! It doesn't wrinkle easily so its a great dress to pack for trips. I just love it!