Smells like teen spirit? Hardly—the new wave of '90s nostalgia on the runway is more about refined and refreshed looks of rich plaids than unwashed hair and flipping the bird. Unexpected combinations of the famous check with supple leather blocking and mod hardware details breathe new life into the era's staple fabric, and the sleek lines of Céline’s tartan coats (and Marissa Webb’s painted plaid midi dresses!) are anything but grungy. For the office, look for clean silhouettes—think sleek trousers or blazer in a darker colour combination: black and white or green and blue. On the weekend, slip into a pair of broken-in boyfriend jeans with a soft, feminine blouse in a plaid print.