The page number and the running head are the smallest pieces of type in a book. A reader could not tell you what the running head on the last page they read said, and would never count the page numbers. And yet these two marks, more reliably than almost anything else, separate an interior that was set by a publisher from one that was printed from a word processor. They are small, they are dull, and they are exactly where care shows.
The reason is that they obey firm conventions, and the conventions are easy to break without noticing. A folio that drifts, a running head printed on a blank page, page numbering that counts the title page as page one — none of these is a dramatic error, but each one signals, quietly, that the book was not finished by someone who knew the rules. So it is worth knowing them. They are one of the finishing details in the broader walk-through of how to format a book interior for KDP.
The two marks, and their proper names
A folio is the page number. A running head (or running header) is the line of type along the top of the page that names something about the book — most often the author's name on one side and the title or chapter on the other. When the same line runs along the foot of the page instead, it is a running foot, and the folio often lives there.
Both exist to orient the reader: the folio tells them where they are in the book, the running head tells them what they are reading. Neither should draw attention to itself. They are set small, in the same family as the body type or a quiet companion to it, and they sit in the same place on every page so the eye stops seeing them.
Where they sit on a spread
A book is read as two-page spreads, and the two marks are arranged to mirror across the gutter — the inner margin where the pages meet.
The left-hand page is the verso (the even-numbered page); the right-hand page is the recto (the odd-numbered page). The convention that almost every book follows:
- Running heads are mirrored. The most common scheme puts the author's name on the verso and the book's title — or the current chapter title — on the recto. They are set toward the outer edge or centred, never crowding the gutter.
- Folios sit at the outer corners or centred, at the top or the foot. The one rule that never bends is that the folio is always present and always in the same position, so a reader flicking through can find their place.
The mirroring is the part hand-formatting tends to miss. A running head that reads identically on both pages, or a folio that sits inboard near the spine, reads as not-quite-right even to someone who could not say why.
The pages that suppress them
Not every page carries a folio and a running head. Several pages deliberately drop one or both, and knowing which is most of the craft.
- Chapter-opening pages suppress the running head entirely — a title sitting above a chapter title is clutter — and usually drop the folio from the top, often keeping it at the foot. The full opener treatment is in formatting chapter openings and headings.
- Front-matter display pages — the half-title, title page, copyright page, dedication — carry no running head and usually no visible folio, even though they are counted.
- Deliberate blank pages — the empty left-hand pages that fall so that the next section opens on a recto — carry nothing at all. A running head or folio printed on an otherwise blank page is a giveaway error.
The principle underneath all of these: a page that is a display or a deliberate blank stays clean. A page of running text carries its marks.
Numbering the front matter
Here is the rule that trips most people, because it runs against intuition. Page one of a book is not the first physical leaf. It is the first page of the actual book — chapter one, or the introduction — and it is conventionally a recto.
The front matter is numbered too, but separately, traditionally in lower-case roman numerals (i, ii, iii) that are usually counted but not printed on the display pages. So the half-title is page i, the title page ii, the copyright iii, and so on, even though none of those numbers appears on the page. Then, at chapter one, the count restarts at arabic 1.
Why bother? Because it means the page numbers a reader actually sees begin at the start of the book, where they expect, rather than counting four or five pages of front matter into the body. A book that numbers its title page as "1" and reaches "9" by the time the story starts has skipped this convention, and it shows.
Where these go wrong
Almost every folio-and-header fault is one of a small set:
- Running heads on the wrong pages. A running head printed on a chapter opener, a blank, or a front-matter display page. The fix is to suppress them where convention says, not to print them everywhere.
- Heads that do not mirror. The same text on verso and recto, or the author's name on the right-hand page. Set the verso and recto differently.
- A drifting folio. A page number that moves position from page to page — inboard on one, outboard on the next. It should sit in exactly one place throughout.
- Front matter numbered into the body. Counting display pages as arabic page 1 onward, so the story starts deep in double figures. Number the front matter separately, restart at chapter one.
- A folio inside the safe margin. A page number set so close to the trim edge that it risks being clipped, or so far into the gutter it disappears into the binding. It has to sit within the same safe area as the text, a concern that ties directly to margins and the gutter.
None of these is hard to avoid once you know to look. They are simply easy to miss, because the marks are so small that they are the last thing anyone checks — and the first thing a careful reader, or a print-on-demand reviewer, notices.
Where Folio Format fits
The trouble with folios and running heads is that they are governed by rules about which page this is — opener or body, verso or recto, front matter or chapter one — and a general word processor does not know any of that. It treats every page the same and leaves you to suppress and mirror by hand, which is precisely how a running head ends up on a blank page after a late edit shifts everything along. Folio Format treats the running head and the folio as properties of the book that respond to what each page is: openers suppress their heads, blanks stay clean, the verso and recto mirror, and the front matter numbers separately from the body — without any of it being set page by page. Because the rules belong to the book rather than to individual pages, an edit that moves the pages around does not leave a folio stranded in the wrong place. It is designed to help you export KDP-ready files and catch common publishing issues before upload, and a clean, correctly numbered interior is one of the quieter ways a book earns a reader's trust.
Last checked 26 May 2026. Always confirm current Amazon KDP and IngramSpark specifications before uploading final files. Folio Format is designed to help users export KDP-ready files and catch common publishing issues before upload; it makes no claim about platform acceptance.