Returns or sets the width (in points) of the borders surrounding the frames on the specified frames page. Read/write Single.
For more information on creating frames pages, see Creating frames pages.
This example sets the width of frame borders in the specified frames page to 6 points.
With ActiveWindow.Document.Frameset
.FramesetBorderColor = wdColorTan
.FramesetBorderWidth = 6
End With