|Actual backpack being used in the field.|
As a former Eagle Scout, soldier, and knockabout guy traveling around, I instinctively know about backpacks. Durability is always the absolute first thing one must look for in a backpack.
If I was a backpack innovator I would choose children for my R&D as they really put backpacks through their paces. They beat on the things hard, cram as much stuff as possible into them, and demand a certain level of fashion.
Here are a few seconds of the journey to school:
To get a few years use out of a school backpack is a victory.