Ralph Lauren Purple Label - The buckled side adjusters of Ralph Lauren Purple Label's black Gregory trousers are a testament to the label's reverence for time-honoured details - see how the waistband layers flatteringly beneath blazers, knits and outerwear. Twilled from cotton that's eased by a hint of stretch, they're lined to the knee of the slim legs with smooth satin, then finished with pockets at the sides and back.