“Waterproof” and “water-resistant” are not interchangeable backpack terms. A water-resistant backpack can handle some rain or splashes. A waterproof backpack is designed to prevent water entry to a much higher degree through its fabric, seams, zippers, and closure system.Quick Answer: Most everyday school, work, and travel backpacks are water-resistant, not fully waterproof. Their fabric may repel light rain while standard seams and zippers remain...