Types

• Backpacking backpacks fall into two broad camps: external frame and internal frame. The traditional external frame packs do well carrying heavier loads. But they have fallen from favor in recent decades. Internal frame packs, which were invented in 1967, are now the most popular backpacking backpacks. By shifting more weight onto a hiker's hips, these packs provide for better agility and balance.
  
  

Size

• Backpacking backpacks should be sized to a hiker's torso instead of his height. To determine torso length, measure from the base of the neck to the hipbone. Ideally a backpacking backpack should have 3,000 to 5,000 cubic inches of space for overnight or multi-day trips.
  
  

Features

• Most backpacking backpacks have a roomy interior for storage with a sleeping bag compartment. Along with adjustable shoulder straps and a sturdy hip belt, many packs feature external pockets for quick access to certain items, water holders, space for a hydration bladder and a removable cap section.
  
  

Packing Advice

• It's wise to take a backpacking backpack out on a day hike or two before your first overnight or multi-day trek. Learning to properly distribute gear in a backpacking backpack requires practice. A sleeping bag and pad should go at the bottom of the pack to keep the hiker's back straight. Placing a tent on top will act a counterweight. Food, clothes and other gear go in the middle. The outside pockets are for personal supplies and small items.
  
  

Warning

• Because external-frame backpacking backpacks have a high center of gravity, they're more suited for less difficult terrain. Don't try biking or skiing with an external-frame pack.