I bought this at the same time I bought some "loose" swing tunic dresses. This one fits me so much better, though I love both styles. This dress is more form fitting, but in a forgiving way. The material of two of these is slinky and smooth. I don't have to wear anything under it. It's not thin, but thin enough to wear on a hot summer day. The length isn't too short. I feel like mine isn't as short as the model. However, I am busty and I purchased an XL because of that. I purchased the black with white stripes, white with black stripes, and navy with white stripes. The first two were that same slinky material. The navy one is considerably thicker and I have to admit that while I like it, I haven't worn it yet due to the material. It's not slinky. It doesn't have a shine to it. It's like a thick (but not stiff) t shirt almost. I don't remember reading about different materials, and they don't look different on the model, which is interesting because they are very similar but I can tell the difference instantly when held up next to one another.