Even if you opt for a durable backpack, you should consider storing your laptop in a protective sleeve inside the bag. A sleeve can keep out any dust or dirt that is bound to accumulate at the bottom of your backpack. And if your backpack isn't waterproof and you leave your water bottle unscrewed by accident, a sleeve can provide an additional layer of protection. A sleeve might also help with any jostling if your backpack's laptop pocket is a bit too big.