The standard medieval margins were in general more generous than those we have in todays books. A common layout traditionally had more space at the bottom, and on the outside margins, as compared with todays books, where margins can be a mere 10 millimetres wide. It varies a lot where page numbers are placed in printed books. Sometimes page numbers are placed at the bottom of the page, sometimes at the top; sometimes the page number is placed to the right, and sometimes to the left, or in the middle of the page. Usually page numbers are placed at the bottom of the page.