Your Backpack

   I first mentioned the backpack in What to Bring Part 1, and it's about time to look at it in more detail. There are a lot of different things to look for in a backpack, and it helps to know what's useful.
   If you're just making a short trip, or don't feel like more than the essentials; then you can just grab a small daypack. Whether it's a school-style backpack, or an ultralight hiking pack, a daypack is a small, frameless pack that won't stand out too much, and won't get in the way. If you're planning on carrying less than 20 or 30 pounds, this is the best bet. They usually don't have too many extra features, so there's not much to know about them.
   Most larger packs (and some daypacks) come with a hip-belt. This is a set of wider, usually padded, straps that buckle around your hips. When your pack is all properly adjusted, and the hip-belt is clipped, it shifts most of the weight off of your shoulders and onto you're hips. You should feel about 2/3 of the weight on your hips, and only 1/3 on your shoulders. This lets your legs do most of the work, and lowers the risk of seriously messing up your spine over time. Use this as often as you can, even if you're only walking a block, it'll save a lot of energy.
   Between the shoulder straps, you'll find a smaller strap with a buckle. This is the sternum strap. It's height can be adjusted, as well as it's tightness. This strap shifts a lot of the weight from the shoulder muscles to the chest. Between the sternum strap and hip-belt, you shouldn't have much weight on your shoulders. This is important, because your shoulders wear out easily, and since they connect to your spine, can make your whole back hurt if they're strained or unevenly loaded.
   External frame packs have a large, usually metal, frame, onto which the pack itself is attached. Other items, like sleeping bags and pads, smaller bags, tents/tarps, etc can be lashed onto this frame, making it more versatile than internal frame packs and daypacks. They're a lot cooler in summer, since the pack itself isn't resting against you (nearly a foot of insulation on your back gets annoying fast). They're often cheaper than internal frame packs too, so they're pretty common with beginners, or as quick replacements to damaged packs.
   Internal frame packs have a frame inside the back panel. It's usually either plastic or aluminum. The aluminum ones are often adjustable, which is nice, but not something to worry about early on.  Internal frame packs also tend to have a more complex suspension system. In my opinion, they're more comfortable, and I prefer them over external frames. The lack of metal bits jutting out means that internal frames are less likely to get caught on things, easier to cram in car trunks and other tight places, and they aren't as likely to get messed up if you have to toss them over a fence.
   Along with being able to adjust the length of the shoulder straps, on internal frame packs there will be another set of straps where they connect to the top of the pack; these are the load lifter straps. Tightening them pulls the top of the pack closer to you're back, raising the center of gravity of the pack. When properly adjusted, these will form a  45 degree angle from the shoulder straps to the pack. With a higher center of gravity, you won't be bending forward as much while walking.
   There may be similar straps where the hip-belt attaches to the pack, called stabilizer straps. These help pull the pack in closer to your back. Not all packs have them, but they're on quite a few.
   On the back of many packs, you'll find straps going around the pack itself, but not connecting to anything else. These are compression straps. they're used to keep the load from shifting around too much. They can also be used to hold your tarp, cardboard, sleeping mat; just don't overload them, they aren't meant to hold much weight. Some top-loaders will also have similar straps on top specifically for holding tarps and sleeping mats.
   Some packs will have straps dangling off of the bottom, these are to hold your sleeping bag in its stuff-sack. Other packs will have an extra compartment on the bottom for this. I prefer the enclosed compartment when I can get it. It helps keep your sleeping bag from getting too messed up.
   When loading your pack, you want to keep the heaviest items, like any canned food or bottles of water, higher up, and as close to your back as possible. Keep the lightest gear, like sleeping bags, on the bottom. This way your center of balance is a bit higher, and you won't have to bend forward very far to keep your weight centered over your feet.