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.
It is very important to bear in mind though that the temperature rankings are overviews for recommendation only. Because, much like spicy food, consuming a jalapeno pepper for some isn't really a big deal ... but for others eating one would certainly seem like it would melt the skin straight off their tongue. The exact same goes with a sleeping bag. A +20 level rating would indicate that for most the bag would certainly be cozy sufficient. The most effective way to pick a cozy enough bag is to go with one that handles a 10 degree chillier weather condition than what you're anticipating to be sleeping in. Selecting in that manner needs to have you ... covered. (No pun planned.) And once more of course, appropriate sleep wear should fit the chillier or warmer demands you may have.
Rectangle-shaped shaped bags are one of the most popular and also most acquainted. These supply you with even more space for movement within, lowering that claustrophobic feel to some degree. Since they are of a square form they could also be whized to a 2nd to generate a double sized resting bag, huge enough for two individuals to sleep in. Or, if you completely do not like the feeling of being zipped up, you can leave the bag unzipped completely and also utilize it as a blanket rather. These bags are typically rather huge, and also might not be perfect for treking trips as they can be instead bulky and unpleasant to carry.