Almost every difference between ebook and print formatting follows from one fact: a reflowable ebook has no fixed page. The reader's screen size, font size and margins decide where lines break, so anything defined in terms of a page has nothing to attach to.
That single change removes page numbers, running heads, widow and orphan control, the gutter, and the recto rule all at once.
Reflow Is the Default, Not a Setting
EPUB 3.3 treats fixed pages as the exception. A fixed-layout document is defined as one "with fixed dimensions directly referenced from the spine", designated "pre-paginated in the package document". Reflowable is what you get by declaring nothing, which is covered in reflowable vs fixed layout.
So the print habits below are not disabled by the ebook format. They simply have no referent.
What Has No Meaning in an Ebook
Page numbers. There are no pages to number. An EPUB can carry page numbers, but only by importing them from a printed edition, and the spec requires you to say which one: "When an EPUB publication includes page break markers and/or a page list that correspond to a statically-paginated version of the publication, EPUB creators MUST identify that source in the package document metadata."
The DAISY Consortium explains why the declaration matters: "a student in a classroom, for example, needs to know whether the pagination was derived from the same version of a print book that the rest of their class is using." Page numbers in an ebook are a reference to a print edition, not a property of the file.
Running heads and feet. They live in a page margin, and there is no page margin.
Widow and orphan control. A widow is a line stranded at the top of a page. With no fixed pages, there is no stranding to prevent. In print this is a real craft concern, covered in widows and orphans in typesetting.
The gutter. That margin exists because a physical book is bound. Nothing is bound.
Recto and verso. No left and right pages, so the rule that chapters open on a right-hand page does not apply, and neither do the blank pages inserted to satisfy it.
Trim size. The page is whatever the reader's device is.
An honest caveat on all of this: these follow from the absence of pagination rather than from any prohibition. I could find no statement in EPUB 3.3 saying running heads or widow control are unavailable. They are simply undefined, which amounts to the same thing in practice.
What Changes Rather Than Disappears
Type size becomes a suggestion. This is more nuanced than usually claimed. EPUB Reading Systems 3.3 says reading systems "SHOULD apply EPUB creator style sheets as written" and "SHOULD NOT override the EPUB creator's style sheets", but "MAY override parts of the EPUB creator's style sheet because of user interaction."
So reader override is permitted, not guaranteed. There is no requirement that a reading system expose font controls at all. Design as though your CSS will be respected and as though it might not be.
Images need relative units. DAISY names the failure directly: "Styling elements using absolute units like pixels, as the visible screen area is reduced, these units cannot adapt to the changes but stay fixed (i.e., forcing scrollbars)", and prescribes "Use relative size units for container elements". Anything in pixels breaks on a phone.
Chapter breaks become file breaks. In print a chapter starts on a new page. In an ebook it starts a new content document, and the spine's order is what defines the reading order, as covered in accessible EPUB structure and reading order.
The table of contents becomes mandatory. Optional in a print novel, required by the spec in an EPUB. See do novels have a table of contents.
Front matter gets reordered. Many digital editions move copyright information to the back, since a reader sampling the opening should reach the story quickly rather than four pages of prelims.
What Carries Over Unchanged
Less changes than the list above suggests:
- Chapter and section hierarchy. Headings do more work in an ebook, not less, since they are how assistive technology navigates.
- Scene breaks. Still needed, still marked with a glyph rather than blank space, and for the same mechanical reason plus a new one: white space is even less reliable when the reader controls the layout.
- Italics and emphasis. Semantic, not positional.
- First-paragraph treatment. Flush left after a heading or scene break still reads correctly.
- The text itself, obviously, which is the point.
What This Means Practically
You are producing two different objects from one manuscript, not one object in two wrappers.
The print edition is a designed artefact where you control the page. The ebook is a stream of structured text where you control the semantics and the reader controls the presentation. Trying to make an ebook look exactly like the print edition means fighting the format, and usually means reaching for fixed layout, which costs the reader font control for no gain in a novel.
What Deckle Does
Deckle produces both from the same manuscript, applying each set of rules to the format it belongs to rather than making you maintain two files.
Print-only settings stay print-only. Trim size, margins and gutter, bleed, running headers, page number position, widow and orphan control, and the recto chapter rule all shape the PDF and are simply not emitted into the EPUB. There is nothing to switch off.
Shared settings apply to both. Typeface, scene break style, first-paragraph treatment and chapter heading structure carry across, with the EPUB expressing them as CSS and semantics rather than as fixed positions.
A few behave differently by necessity. Drop caps render as a styled first letter rather than a precisely measured three-line drop. Images are sized as a percentage rather than in inches. The table of contents is optional in print and, as noted above, required in the EPUB.
The practical consequence is that switching a project between print and ebook output does not require re-formatting it, but it does require looking at both. The device preview is worth using before you upload, because a layout that reads well on a designed page is not automatically the one that reads well at 200 percent font size on a phone.
For the format decision itself, see EPUB vs PDF vs DOCX.
Common Mistakes
- Trying to reproduce the print layout in the ebook. You are fighting the format, and the reader loses.
- Typing page numbers or cross-references into the text. "See page 142" is meaningless in a reflowable file.
- Sizing images in pixels or inches. They cannot adapt, and DAISY names this as the reflow failure.
- Using blank lines for scene breaks. Even less reliable than in print.
- Assuming readers can always change the font. The spec permits override; it does not require it.
- Skipping the ebook proof. The two outputs need looking at separately.
FAQ
Q: Can an ebook have page numbers? A: Only by importing them from a print edition, and the spec requires you to declare which edition they came from.
Q: Why does my ebook ignore my margins? A: Margins are a property of a fixed page. The reading system sets its own.
Q: Do I need two versions of my manuscript? A: No. One manuscript, two exports, with the print-specific settings applying only to the PDF.
Q: Should I use fixed layout to keep my design? A: Not for a novel. It removes the reader's font control and the specification warns about the accessibility cost.
Q: Do scene breaks still need a glyph? A: Yes, and more so. The reader controls the layout, so white space alone is unreliable.