It’s unlined but not sheer since it’s black. I’m not sure of the fabric but it’s very silky and flowy. Great dress to wear to a pool as a cover up, or on a warm sunny day. Great for travel, packs very small and light. Maxi length, about 53 inches long, with high slits on both sides. It’s labeled M/L but I think it would be too tight across the chest for an L. M is more accurate for sizing. Excellent used condition. Message me with any questions!