1, warmth: the formation of tiny air pockets between the fibers of white duck down can effectively prevent the dissipation of heat, providing better insulation. Cotton does not form a similar air layer structure between its fibers and has weaker warmth-keeping properties.

2, fluffy and light: white duck down fibers are larger and less dense, in the same weight, white duck down can occupy more space. This makes the clothing filled with white duck down more fluffy, can better maintain the air layer, providing better insulation. Cotton fibers are relatively short, dense, filled with clothing is relatively heavy, not as light as white duck down.