However, these boxes proved not to be durable, as, unlike their counterparts on ships, they needed to be unloaded at each nightly stop. At some point, an entrepreneur tackled this issue by creating a leather case with rigid sides and additional locks. This proved to be lighter and far more durable than wooden boxes, thanks to its flexibility. These lid-covered cases endured until the emergence of airlines, which required lighter luggage. This, coupled with the Industrial Revolution, led to an explosion of leather goods designed to meet all new needs—business bags and folders, writing cases, leather wallets, leather bags, and more.