Just in case you do not know, "watteau" style means fits in front, flows in back! There is great back interest indeed in this flowing chiffon gown. Color is lime green? Mint green? Looks like a prom gown from the 60s. It has a back nylon zipper, so more mid to late 60s. Sleeveless (like you couldn't see that), empire waist in front, flows free in back. Rayon crinkle chiffon over acetate taffeta that is a pale yellow, giving this an iridescent effect. It is REALLY small and there was no way it would fit on model OR mannequin. NOT PERFECT: it has a small hole in chiffon, which gets lost in folds, one mended hole down by hem in back, and a faint stain at side in front, all pictured. I took a chance and had it dry cleaned, but there are marks in the taffeta lining that do not show through to front.
MEASUREMENTS (it's a small one!)
bust 30"
high waist 26"
length 49"
31

This item is sold from an excellent, highly rated vintage boutique in Northfield, OH.