Semi-Rectangular: I call this the cross. This backpacking bag is rectangle-shaped ahead and afterwards slenders along towards the feet. With this type, you obtain added space, but not as much weight as a true rectangular resting bag. For those who are claustrophobic, like me; we can reach sleep a little better inside a bag with added room in it and still have some benefit from the form.
Remember that with time, from typical use, a treking sleeping bag will certainly lose its warming performance. This results from the fill obtaining a bit much more compressed. This will cause the "air pockets" to go away.
Prior to establishing your backpacking bag, be sure you shake it out a number of times. This will certainly help "fluff" it up and also increase the airspace. If your bag includes pockets, be cautious with simply what you determine to put in them. Prior to buying the bag, take note of the pockets different places.