Mantle, (Mantling, or Cappeline, fr. Lambrequin): this device of the painter to give prominence to the coat of arms and crest in considered in theoretical heraldry to represent the lambrequin, or covering of the helmet, to protect it from the sun or rain. Some authorities contend it should be of the principal colour and metal of the bearer's arms, but red and white have most frequently been used in England. The Royal mantling should be of gold and ermine; that of peers is often of crimson(representing crimson velvet), lined with ermine. This kind of mantle cannot be used by ladies, being inseparable from the helmet.
The Robe of estate, however , may be used as a mantle(fr. manteau), is which sense it may be borne by all ranks of gentlemen, and by peeresses, and it represented as encircling the crest, if any, and the whole of the shield or lozenge with its external appendages. The mantle may be embroidered on the outside with the arms, or be powdered with heraldic objects.