Inheraldry, abordure is a band of contrastingtincture forming a border around the edge of a shield, traditionally one-sixth as wide as the shield itself. It is sometimes reckoned as anordinary and sometimes as a subordinary.

A bordure encloses the whole shield, with two exceptions:

• When two coats of arms are combined byimpalement, the bordure usually stops at the partition line and does not run down it, as shown in thearms of Kemp as Archbishop of Canterbury in the 15th century; this rule is considered a relic of the older practice ofdimidiation. However, a notable exception to this rule can be seen in the arms ofThomas de Holland, Duke of Surrey (a nephew ofRichard II) from a drawing of his seal, 1399, showing a differencing of a full bordure ermine, and a full bordure argent.^[1]
• Achief overlies a bordure, unless the bordure is added to a coat that previously included a chief, or so it is often said. In practice, the order in which things are to overlie each other can usually be inferred from the blazon. For example, in the arms ofAmber Valley Borough Council, the blazon describes the bordure before the chief, and the bordure does not surround the chief; while in the arms of theBritish Columbia Institute of Technology, the blazon specifiesa chief ... within a bordure.

Like any ordinary or other charge, a bordure may be of a single plaintincture ordivided. Like any ordinary, it may be smooth or subjected to any of thelines of variation; it may form a field for other charges. These variations are effectively exploited in the Scottish system ofcadency.

Since it is very often used forcadency rather than to distinguish between original coats, the bordure is not strictly held to therule of tincture; for example, many cadets of the French royal house, for example, bore red bordures on a blue field. Rarely a bordure is of thesame tincture as the field on which it lies; in this case the term "embordured" is employed.^[2] This was a very unusual practice even centuries ago and is all but unheard-of today.

A borduresemy of some charge is shown as if it were charged with a great number of those charges, rather than the practice typical with a field, in which some of the charges are shown as "cut off" by the edges of the field. This large number is to be taken as semy, and not as the precise number shown.

In French heraldry, thediminutive of the bordure, one quarter of its width, is the filière.^[3] In English-language heraldry, the terma bordure diminished is occasionally employed – as in 'Or; a diminished bordure vert; on a chief indented azure, two fleurs de lys or' (127th Field Artillery, US), and 'Or; representations of two San human figures of red ochre, statant respectant, the hands of the innermost arms clasped, with upper arm, inner wrist, waist and knee bands argent; and a narrow border of red ochre' (Republic of South Africa).

• Bordure componée
• Orle
• Fillet (heraldry)

  This article incorporates text from a publication now in thepublic domain: Chambers, Ephraim, ed. (1728). "Bordure".Cyclopædia, or an Universal Dictionary of Arts and Sciences (1st ed.). James and John Knapton, et al.