I went on a two year trip and it taught me a lot about the backpack I want. The first thing you need to know is how big you want the bag. This doesn't have to do with the bag itself, but it's important because you are going to be carrying all that weight on you. I recommend something on the smaller to medium size of backpackers bags (still a large bag, but not gigantic!) and only pack essentials. Living out of a backpack really makes you realize how little you need. When I first started, I packed so much that actually ended up leaving things behind a long the way. I learned very quickly that weight is THE most important part of a bag. I also find it very important to get a bag that has an access point in the bottom as well as the top so you can easily get to the stuff at the bottom of your bag. Being able to get to your stuff is for sure the next most important thing. Some of them even have zippers that open the entire bag. Make sure it has straps to compact the size of the bag and also for attaching any gear you might want to hang off it. Padding on the back and shoulder straps are also important - most come with it, but don't be afraid of giving it a squeeze. Make sure it has a waist strap and a sternum strap as well - those are the ones that come off the back straps and close on your front. Also, you're going to want to get a rain cover - some come with them, but some don't.
I don't have a specific brand I could recommend, only the features I think a bag should have. Likewise, I don't know much about these new fangled fabrics. I would recommend that you get a thick, durable fabric and that you check the seams on any bag you want to buy - make sure they are well sewed/put together.
Hope that helps!
|