The trouble is that when I went to look for my "ideal bag" there was so many choices I really did not know which bag would certainly function best for me. One is the mommy bag and also the various other is the "old school" rectangular sleeping bag. The rectangular sleeping bag isn't as tiny however given that it's not regular to be carrying it, other compared to somewhere in a car while obtaining to your designated destination, the thickness of the bag is not as big an issue.
The other sacrifice is the size or thickness of the bag. A mummy sleeping bag essentially will certainly be much smaller sized for bring around which is why it is a preference for many backpackers/hikers. The rectangular resting bag isn't as small yet because it's not common to be lugging it, apart from somewhere in a vehicle while getting to your intended location, the bulkiness of the bag is not as large a problem.
In 1917 the zipper was developed and, of course, these made for a terrific seal for the rectangular sleeping bags allowing an individuals body warmth to remain trapped longer consequently keeping them warmer on those cold winter season evenings. Basically the term resting bag essentially suggests a safety bag for someone to rest in.