Heraldry: The Field  

The Field is just the name for the background to the Coat of Arms.  There are a number of standard ways the field can be  divided.  The field can be divided :-

Per Pale Per Cross
Per Bend Sinistre Per Saltire
Per Fess Per Chevron
Per Bend

Other divisions might be acceptable, except that the Border is reserved for the awarding of Honors.