Envelope type: optimize space by sacrificing warmth, weight, and packing volume. A good choice for a summer camping trip, but that's all. You don't want to carry an envelope bag for the long haul. They are usually not very expensive.
Mummy: close to your body curve modelling, mummy sleeping bag type in maximum heat preservation of minimizing the volume and weight at the same time, by adding extra hood realized on the shoulder, neck and head of heat preservation.
Semi-envelope type: not comfortable enough in a traditional mummy bag with limited space? There is an envelope type and a mummy style sleeping bag, which provides the space of the former and the thermal insulation of the latter. In most cases, they are slightly larger than the mummified weight and packaging. Each manufacturer has their own style: spoons type, spiral, pyramid or other forms, in common yudu is use a half envelope type design and make sacrifices for the mummy on the weight increase comfort.
Bed type: a new sleeping bag designed by Sierra Design, emphasizing the comfort of different sleeping positions (side lying, lying, lying down) without sacrificing heat preservation, but making sacrifices for weight and packing volume.
Quilts: their packing volume and weight have been greatly reduced because they have abandoned the thermostatic portion of the bottom. You need to use a warm moisture-proof mat to work with them, just as you do with other sleeping bags. Some of the quilts include the package and hood of the foot, but the original design is a tile square. Their use is more flexible than it sounds, and in the warm night you just stretch your legs out under the covers and pull them down to adjust to the temperature. However, it takes some practice to keep the maximum heat and sleep comfortably in the quilt. It's a good choice for a lightweight summer backpacking camp, and it's a good way to add another sleeping bag in the winter.
Integrated cushion type: gold standard. Similar to the concept of quilts, comfort, insulation, stability and security are all better designed to be realized by integrating sleeping bags and moisture-proof pads (usually modular). This design minimizes weight and package volume. However, you need to buy a combination of sleeping bags and moisturisers at the same time, and usually only well-known brands will produce this product, so they may exceed some people's budget.