This is a vintage mid 90's sexy, vamp dress by designer Helmut Lang. The black fabric is made of jersey with a stretch to it; I couldn't find a content tag but it is likely made of wool, cotton, and synthetic fibers. The fabric has some give so it will hug your curves just so.
It is made with an elastic underneath that pulls the waistline and the whole right side up. It's very unusual.
Shown with a black bra underneath, so under the bright lights, it became a little see through. No lining, no zipper. Designer quality is evident.

Label is "Helmut Lang." This designer dress is unworn, with the original tags still attached. Originally priced for $730 but was purchased on discount at Saks off 5th. There is the Helmut Lang tag, the Saks tag, and the price tag. I have shown both side of the tags. This came from a collection of unworn vintage designer clothes which I am listing slowly. Beautiful!

The dress is tagged as a size 42, model is modern 7/8. The ruching was just a tad tight on her and this would best suit a smaller size. Made in Italy.

Label: Helmut Lang
Original tags: Yes
Size: 42 Italian, US 6
Made in Italy
Model is a modern size 7/8

Measurements laying flat-- and then stretched a bit:
Bust 32-38"
Waist 24-32"
Hips 30-36"
Shoulders 15.5"
Length from collar to hem 50.5"
Sleeve length 23"