Packing and Camping
The 'Big Three"
Ultralight Backpack - Approximately 35 liters would suffice for a middle-of-the-road, ultralight carrying capacity. Consider internal frames or frameless options, the latter being the lightest.
Ultralight Shelter - Many ultralight options available, for example: the standard tent-and-pole option, tarp tents (a lighter weight version of the tent-and-pole option), or a simple tarp. Shelters are made from a wide array of materials, all having pro's and con's. Another option is a hammock with a tarp over the top to protect from the elements. An ultralight hammock can ensure that nothing will be wet from contact with the wet ground during a precipitation event. I have used an ultralight hammock for many-a hundreds of miles, and I love the comfortability.
Ultralight Sleeping Bag - There are different opinions about which kind of sleeping bag to use for an ultralight backcountry experience. The main question is sleeping BAG vs. QUILT. A sleeping bag is a traditional insulation layer that wraps entirely around the camper and typically has a zipper. Sleeping bags may also have a 'mummy-style' hood that wraps around the head of the sleeper, making the entire system an enclosed insulation layer. On the contrary, a sleeping top-quilt, originally designed for use in a hammock in conjunction with an under-quilt, typically does not have a zipper of any sort; it simply lies on top of the sleeper and wraps slightly around, similar to a household blanket, and completely encloses the feet, creating what is known as a 'foot box.' If one decides to use a hammock and tarp as a backcountry, ultralight sleep system, the quilt is a fantastic way to save weight.
Ultralight Sleeping pad - A sleeping pad boils down to the amount of comfortability and warmth a backpacker needs when in the backcountry. Sleeping pads are rated to an R-value, which measures how much heat will be transferred throughout the material from the body - the higher the number, the 'warmer' the sleeping pad and sleeper. The least amount of padding and insulation one can have under their body during the night is, well, nothing, and I have seen people do this before. It is possible in the summer, and the ground can be comfortable. But these people are few and far between - a little too ultralight for my taste. Closed cell sleeping pads are a standard 'foam' pad, which come in a variety of shapes and sizes. Inflatable sleeping pads are generally heavier and require a few minutes to blow them up before sleep, but generally offer more padding. Inflatable pads are more expensive and can leak air from small (or large) punctures in the material. Regardless of choice, a sleeping pad can double as a frame in frameless backpack. A great example is the ULA CDT ultralight backpack, my choice for over 2000 miles on the Appalachian Trail. Also, if one decides to use a hammock as a sleep system, a sleeping pad underneath the quilt or sleeping bag is necessary for insulation on the backside if the sleeper does not use an under-quilt.
An ultralight "Big-3" set-up typically weighs anywhere from 2-8 pounds. My set-up for an Appalachian Trail southbound thru-hike in 2011 was as follows:
Ultralight Backpack: ULA CDT ($135) : 1 lb, 1 oz (some areas of the pack trimmed to my liking)
Ultralight Shelter: Jacks-R-Better Hex Tarp, Spinnaker ($120): 12 oz. with tie-out lines
*Ultralight Hammock: Hennessey Hammock Ultralight Backpack Asym, no tarp (see above) ($230): 1 lb.
Ultralight Sleeping Quilt: Warbonnet Mamba, Regular ($255): 1 lb. 3 oz
Ultralight Sleeping Pad: Thermarest Z-Lite ($30): 10 oz. (cut to 3/4 length)
*I sent the hammock home after a few hundred miles and slept entirely in the many shelters found along the Appalachian Trail.
Total Big 3 weight and cost for long-distance Appalachian Trail thru-hike: 4 lbs. 10 0z without the Hennessey Hammock and $540
Happy Ultralight Trails!