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.
These fit perfectly. I bought Medium-and I'm about a size 8-10 typically. They are lightweight and beautiful. I will probably wear them out and about-they look too nice to only wear as pajamas