Courier bags have been around since forever, at first they weren’t known as fashion items but more like useful bags that different types of workers used to carry things around. However, they became a major hit after the 50s when they were manufactured by De Martini Company. They were widely used by the Royal Mail carriers in the UK and that’s the main reason why people associate them with mail carriers. The original De Martini bags were made with cotton and waterproof lining and they were worn with the help of a shoulder strap. Bags also had an inside pocket. Nowadays, courier bags have many pockets and come in all sizes and shapes.