A leather blazer is tailored like a suit jacket, with a lapel collar, a structured shoulder and flap or chest pockets. Double-breasted styles overlap at the front and look best fastened. Oversized cuts are designed to sit loose, so take your usual size rather than sizing up. Each blazer can be made in genuine or faux leather and is lined in soft polyester, which helps it slide over knitwear and shirts. Wear it over a dress or with straight trousers for the office, or with jeans and a T-shirt off duty. Blazer lengths vary between styles, so check the sleeve and body length on the size chart.