This dress is 100% polyester. This is lined, so no slip is needed. This runs true to size. There is a zipper on the side under the arm which makes getting this on and off easy. There is plenty of stretchy in this dress so that zipping the zipper is not difficult even if you're busty. Length is approximately 27" inches from under the arm to the bottom hem. This looks cute worn as pictured or with a belt. Second photo shows the back.