Look for a backpack with padded shoulder straps that are adjustable. Make sure the backpack is not too big or too small. This means that when the pack is properly adjusted, the straps are not fully pulled in or let out. It also means the backpack should not sag down below the waist.

Look for a backpack that has a waist and/or chest strap to help spread out the weight. Finally, look for a pack that has separate compartments to hold things. For example, a separate, side holder for a water bottle can keep that one-pound weight from being lumped inside with all the books. Additional separate compartments can help distribute the weight in the same way.