How light is light? Lightweight backpacks weigh less than three pounds, a standard I just invented. There are good packs under three pounds for almost all types of trips. My own Golite backpack weighs just 14 ounces, and has a capacity of 2900 cubic inches, plus 1000 more in the extension collar. It's more comfortable than any frame pack I've used, but then I don't carry more than 20 pounds in it.

The mesh outer pockets are a great idea. I stuff my wet tarp in the large one in the morning, where it's easy to take out to dry later. I've had my GoLite for ten years. I've used it from the rain forest to glaciers at 20,600 feet on two trips to Ecuador, as well as in the Rockies, the Smokies, and in Michigan. Packed right, it qualifies as carry-on when I fly (I don't like to check luggage).

My next pack will probably be the tougher GoLite Gust, which weighs 20 ounces. I just read seven reviews, all of them praising the pack. One reviewer used it for the weekend with a 27-pound load, so a lightweight backpack doesn't have to be light-duty.

Using Frameless Lightweight Backpacks

Like mine, many lightweight backpacks don't have frames. I use a sleeping pad for a frame, as is recommended. Some backpackers just put the pad in the backpack loosely rolled, with everything inside it. I've found a better way.

Take a closed-cell pad, like the cheap blue ones, and cut it across, halfway through the foam, on opposite sides. You can accordion it into a three layer thick (2 cuts) or four layer thick (3 cuts) back-padding frame. The "hinges" thus created last a long time. Put the pad in the pack, (against your back) and load everything in behind it.

Other Backpack Options

If you want lightweight AND cheap backpacks, start experimenting. I've used an old aluminum pack frame and large duffle bag, to create a full-suspension pack that weighs just two pounds. Though it carried loads well in the mountains of Montana, it wasn't the most convenient to use. By the way, it is lighter than any frame pack I've ever seen advertised.The 8-ounce duffle works okay as a backpack by itself too.

I recently bought a lightweight backpack at Walmart. It weighs six ounces, and it is actually comfortable. It's a daypack, but large enough for overnight hikes, since I travel really light. It cost just four dollars. Lighweight backpacking gear isn't always expensive.