Paul Smith London, a fantastic line of formal wear from one of our most frequently posted-about designers, brings us this elegant waistcoat just in time for a season of summer functions. This wool-blend waistcoat features a grey front and purple viscose back, rear pleats, and an adjustable cinch back. Originally part of a three-piece suit, this piece is refined enough to be worn without the jacket, making it perfect for looking sharp even in the warmer weather. Available now at Mr. Porter.