Showing page margins
You can display the margins in Layout mode exactly as they will print. (Page margins always show in Preview mode.)
To show page margins:
In Layout mode, choose View menu > Page Margins. The margins appear as a thin, dotted line around the edges of the layout “page.” Page breaks appear as heavy, dashed horizontal and vertical lines.
To hide margins:
When page margins are showing, choose View menu > Page Margins.
Most printers can't print to the edge of the paper. If you place objects in the margins or outside the area the selected printer can print to, you see them in Browse and Find modes but don't see the objects when you preview or print.
Note  Page margins do not display if the layout contains one or more navigation parts.
Related topics 
Specifying page margins
Previewing data on a layout