Down is made of the breast coat feathers of ducks and geese. This breast coat is hidden underneath the exterior breast coat that protects the bird from the elements. The older the bird, the softer the down feathers. Polyester or polyethylene terepthalate, is a blend of natural and synthetic chemicals, such as plant cuticles and polycarbonate. Both are used to fill jackets, comforters, and sleeping bags. Hikers, skiers and climbers often have to choose between the two when planning to keep warm for their next trip.
Down works naturally to insulate the human body the same way it does a bird. It traps the heat from the body while absorbing moisture. It releases the moisture into the air without releasing the heat. It is warmer that polyester per unit weight. It’s lightweight and can be compressed for easier packing. Down production is regulated by the government. New Mexico State University professor Susan Wright says that down is easy to keep clean.
Polyester is wrinkle resistant. Polyester is also water resistant and dries faster than down after getting wet. If you are caught in the rain on a hiking trip, the down could take days to dry. Polyester will keep you warm even while it’s wet. It won’t shrink or lose its volume after washing. Polyester is warmer than cotton and other materials because it traps more air. Polyester has been treated with a heat technology that ensures the fibers remain in place for a long time.
Down is expensive. For people who have problems with allergies, down feathers are a poor choice as it tends to gather dust that leads to allergic reactions. Down does not work well when it gets wet. Your body emits moisture constantly as you sleep. If you sweat heavily, down grows to be uncomfortable. Moisture trapped in a down quilt during a cold night can develop into small ice crystals. Over an extended trip, you will notice your quilt gets heavier and heavier as it becomes packed with small ice crystals. Being wrapped in a wet quilt can lead to hypothermia. If you’re traveling to a dry, cool area, choose down over polyester.
Polyester is bulky and doesn’t pack down well, making it difficult to travel with a polyester quilt. In order to provide the same heat insulation of down, polyester ends up weighing much more. If crushed and folded up for travel, polyester doesn’t lose air space, which results in poor performance for insulation. If you’re traveling to a wet, cold area, choose polyester over down.