The stuffing of the duvet is mainly down, and the down is the abdomen of the goose and the duck, and the fluff of the flower of the aloe is called a feather. Because down is an animal protein fiber, it has higher heat preservation than cotton (vegetable cellulose), and the downhole spherical fiber is densely covered with thousands of triangular fine pores, which can shrink and expand with temperature change, and produce temperature regulation function. It absorbs the hot air flowing from the human body and isolates the intrusion of cold air from the outside.

According to the bedding industry standard QB/T1193-2012 standard, the duvet filler composition must be 100% down feathers, and the pile content is 50% or more. The core of the duvet is divided into white goose down, gray goose down, white duck down, gray duck down , a variety of geese and duck mixed velvet. The quality of the core is mainly determined by its standard amount of cashmere and the amount of cashmere.

Their characteristics are as follows: natural goose down: large velvet, small stalk, good quality, elastic foot, warm and strong; duck down: velvet, feather stalk is worse than goose down, but the quality, elasticity and warmth are very high.