Down vs Synthetic vs Cotton Sleeping Bags

Deciding on  a new sleeping bag can be overwhelming


With so many manufacturers out there and so many choices, wading through the options can make you feel more like your drowning. Lets look at a couple of the largest options you’ll have to choose from.

What type of insulating material?

Common insulation types are goose down, duck down, synthetic, synthetic/down blend and sometimes even cotton.

Cotton Fill Sleeping Bags


Cotton has been used for about a couple thousand years for creating linens. Cotton sleeping bags are easily recognizable by their signature flannel design, heavy weight and thickness. Cotton sleeping bags are the cheapest of the three types of bag. However, cotton used as a sleeping bag fill has some very big disadvantages. Cotton fill will lose its insulating properties should the sleeping bag get wet, and if it does get wet then it will soak up water quicker than other materials. Cotton is also heavy which means that to have a bag that is useful throughout the year means lugging around a ten or fifteen pound bag. With these disadvantages, cotton insulated bags really should never be considered an option for backpacking when so many better choices exist. Cotton sleeping bags can definitely be warm and cozy but their place should be reserved for in-home use or car camping in warm, dry weather.

Synthetic Fill Sleeping Bags

Polyester FillPolyester has been around since 1941, today it is the most widely used fabric material in North America. The vast majority of sleeping bags to choose from will have some sort of polyester fill. The reason for this is that polyester fill is generally much cheaper than other materials, but it can also be expensive as advances in production have enabled some polyester fill to have unique properties not found elsewhere. Synthetic fill is generally heavier than down but lighter than cotton. However, some new synthetics are very close to down and even mimic down properties such as lofting well. In addition to their down like properties synthetics are unique in that they are hypoallergenic and maintain their insulating properties even when wet. This makes synthetic fill the only decent choice for people with severe allergies to dander. If price is a concern a synthetic bag will serve your needs with a small sacrifice in increased weight and size.

Down fill sleeping bags

Goose DownThe most expensive sleeping bags are usually one’s filled with down. Down is usually of duck or goose feathers and is generally accepted to be the best option for insulating material. What makes down so prized is its extreme insulating properties given its far lower weight and size. Down compresses more than any other material and weighs considerably less than any other type of fill. Currently, the major disadvantage of down is that like cotton it loses its insulating properties once wet. Some emerging technologies such as DriDown are attempting to lessen this disadvantage. High-end bags treated with this technology promise to be as insulating when wet as synthetic bags. For backpacking down is usually the best choice, down can often compress down to half the size, and is half the weight, of similar temperature rated synthetic. Having a smaller, lighter sleeping bag means less work on the trail and more energy to focus on taking in nature.

With down you also have to decide between duck and goose down feathers. Goose down typically is of better quality than duck as goose feathers are typically acquired from older birds. Down feathers from older birds are typically more resilient and  larger, offering better insulating properties. Typically goose feathers also lack the odors associated with duck. While both types of down are great, people who are extremely sensitive to smell may want to pursue goose down. Goose down will also generally cost a little more than a duck down fill sleeping bag.