Loaded bags were tumbled in a giant, hexagonal spinning drum, soaked in simulated rain storms and lifted and lowered thousands of times. They were then graded on how well they hold up.
The $16 Bakugan didn't do as well, and neither did the $15 Hannah Montana backpack. During one test, the strap failed. Another had a buckle sewn on to the wrong side of the shoulder strap.
One good quality indicator: turning a bag inside out. A backpack is well made if it doesn't have sloppy stitching or loose threads.
Consumer Reports found several backpacks held up very well, including the top-rated Jester by North Face that goes for $55 and the $40 JanSport Big Student.
Aside from quality, a good fit is essential.
"The top of the shoulder strap should be about one to two inches below the shoulder line," Consumer Reports' Alex Willen said. "The bottom of the bag should be no more than four inches below the waistline."