The polka dot pattern is 100% cotton, and the beige side is 100% polyester. There is a tag on the inside of the pocket on the beige side, but I was unable to photograph it. I apologize. The size is not specified, but it was worn from 1 to 3 years old, so there is a sense of use. Since this is a casual inspection, there may be oversights. Please only purchase if you understand that this is a used item.