I freaking love this dress. The material is thin, but not a problem with the black (with red roses). Taking it out of the package I thought it would be too small, but its gorgeous. Just the right amount of stretch. Great for an hourglass figure, especially with the rose design on the hips. I'd wash in cold water, hang up to dry, maybe in the dryer on low for 10 minutes to knock out wrinkles.
(I'm exactly a US size 14, usually wear a 12 in dresses. I got the L in this & its perfect.)