Rare, stunning Bill Blass Collection cocktail dress

Excellent vintage condition Bill Blass one shoulder designer dress. Beautifully constructed with hidden side zipper. No flaws or stains as far as I can tell. Size tag and materials tag are missing, but I’d estimate this to be a size 0-2. Model is size 2. The material feels like a crepe with a heavy tulle for the ruffles. Bottom ruffle is backed with what feels like a heavy satin. Flat measurements Pit to pit: 15” Waist: 14” Hip: 17” Measurement directly above bottom ruffle: 18” Length from shoulder to bottom ruffle: 42”