OK. Do this: Create a new InDesign document (File > New > Document). Make the new doc the same size as your existing printed pages. Deselect "Facing Pages" if the folios (page numbers) are to be placed at the same location on each page. If, on the other hand, the folios locations are different on even and odd pages, then leave "Facing Pages" selected. Open the Pages panel (Window > Pages). Double-click on the Master page icon (or icons) to make them visible. Place a text frame on each master. Insert your cursor in the text frame(s) and choose Type > Insert Special Character > Markers > Current Page Number. Format each folio accordingly (i.e., font, color, weight, etc.). If it's a 100 page document, choose Layout > Pages > Insert Pages and add 99 more pages. Save document. Print a few test pages of the new blank document to make sure the folios are placed and formatted correctly. When everything is good to go, load your existing document into your printer and choose File > Print.
... View more