One cannot directly specify the appearance of edges, between fields, within the XamDataGrid.  One can set how the edges of any Field, which contains data, is displayed.  However if the table contains two lines of fields per row of data then it is possible to have empty fields and therefore missing edges.  our customer was unhappy that sometimes the edges between cells disappeared. 

The Infragistics person which I worked with, case #: CAS-210978-Z9C3B0, suggested that unbound fields could be used to allow those edges to be displayed.  However this lead to multiple issues, one of which had no practical workaround.  Dragging a real field to an 'empty' spot was not allowed.  The real field could only be dragged to the left, right, top or bottom of the empty field. 

Why not allow the edges to be defined for the entire table instead of only allowing them on fields.