Downproofing is a process used to create fabrics that prevent down feathers from escaping while still allowing for breathability. This is achieved through tighter weaves or the application of special coatings, which help retain insulation properties while minimizing leakage of feathers. It is commonly used in jackets, comforters, and sleeping bags to enhance durability and comfort. The result is a lightweight, warm, and functional textile suitable for various outdoor and indoor applications.