in Design
Ebook design is not print design reflowed
An ebook is not a PDF of the paperback. Much of what a print designer controls passes to the reader, and the design has to allow for that.
It is tempting to think of an ebook as the print edition poured into a different container. The text is the same and the chapters are the same, so the design should carry across. In practice, most of the decisions that define a printed book's layout do not survive the move to a reflowable ebook, and trying to force them usually makes things worse.
What the reader controls
In a printed book, the designer decides the typeface, the size, the line spacing, the margins, the page size and where every line breaks. In a reflowable ebook, much of that passes to the reader and the reading device.
Readers can change the font, enlarge or shrink the text, adjust margins and line spacing, switch to a dark background and rotate the screen. The same file might be read on a small phone, a dedicated e-reader or a large tablet. There are no fixed pages: the text reflows to fit whatever screen and settings are in use, so page breaks and the position of a line on a page are not stable.
This is not a limitation to work around. It is the point of the format. A reader with poor eyesight can enlarge the text; a reader on a train can read on a phone.
What that means for design
Ebook design is mostly about structure and restraint. The priorities are clean, well-structured markup, headings that are real headings rather than bold paragraphs, a proper table of contents, and styles that give a sensible default without overriding the reader's choices.
Anything that relies on the fixed page tends to fail. Text placed in precise positions, layouts that depend on a particular line length, running heads and footers, and decorative elements that only make sense beside a specific paragraph all break or disappear when the text reflows.
Some print conventions translate well. Chapter openings can still have a distinct style, with a heading, space above it and small capitals on the opening words. Drop caps are possible, but they render inconsistently across reading systems. Scene breaks can still be marked, though a plain blank line can vanish if it falls at the top of a screen, so a visible ornament is safer.
Images, tables and fonts
Images need to work at many sizes and on both colour and greyscale screens. Text inside an image cannot be resized or read aloud by assistive technology, so it is best avoided, and every meaningful image needs a text description.
Tables are awkward on small screens. Simple tables usually work; wide or complex ones may need restructuring or, as a last resort, presenting as an image with a text alternative.
Fonts can be embedded, provided the licence allows it, but many reading systems let the reader override them, and some ignore embedded fonts by default. The design should still work in whatever font the reader chooses.
When fixed layout makes sense
EPUB 3 supports fixed-layout ebooks, which preserve the page design exactly. They suit picture books, comics, heavily illustrated books and some cookbooks, where the relationship between text and image on the page is the content. For books that are mainly continuous text, fixed layout usually makes reading harder on small screens, because the reader cannot resize the text to fit.
The print edition and the ebook are two different objects. Designing each on its own terms gives both a better chance.