The bow-fastening back on this powder blue dress encapsulates the sophisticated femininity that underpins No. 21’s contemporary aesthetic. It’s crafted in Italy from crepe de Chine spun with silk fibers and is cut with a panelled front that’s ruched to create the impression of a sweetheart neckline. Wear it with pointed pumps and carry a miniature clutch to tap the ladylike mood of the season.