Compression packing is used to lubricate moving parts in machinery. It is typically made of braided fibers that contain lubrication such as waxes and greases. The shape of the braided packing is often a square cross section. Square-shaped packing works well in situations where the equipment is worn and requires good expansion on the packing to create a proper seal. Loosely braided square-shaped packing works well in those situations because when it is compressed it expands better overall than more tightly-braided shapes and, therefore, creates a better seal under pressure in older, loose tolerance equipment.