Dunnage is wood plank boards laid under cargoes to provide ventilation and in some cases assist drainage of moisture from cargoes. Some cargoes require ‘double dunnage’. All dunnage must be clean and free of oil or grease contamination as this could spoil cargo quality. Dunnage can be used as a separation mode between cargo parcels but its prime function is to separate cargo from the steel decks and avoid cargo sweat.