Mantling is blazoned mantled x, doubled [lined] y; the cloth has two sides, one of a heraldic colour (red, blue, green, black, or purple) and the other of a heraldic metal (white or yellow). (See heraldry for more on these tinctures.) The mantling is usually in the main colours of the shield, or else in colours that symbolize the entity bearing the arms. For example, the Coat of Arms of Canada is mantled white and red, or argent doubled gules.
Mantling represents a protective cloth covering worn by knights from their helmets to stave off the elements. Sometimes, mantling is drawn as an intact drape; other times it is shown tattered, as if in battle. This is usually the artist's discretion and done for decorative rather than symbolic reasons.
See also
Shield -- Crest -- Supporters -- Compartment -- Motto