Choose for sustained reading, not a specimen
A typeface that looks elegant in a chapter-opening sample can become tiring over three hundred pages. Set several real pages with dialogue, italics, punctuation, numbers, short and long paragraphs, and the longest names in the manuscript. Evaluate rhythm and recognition at normal reading distance rather than zoomed in on a bright display.
Traditional serif faces remain common in trade print because their forms create a familiar continuous texture, but serif is not a guarantee and sans serif is not automatically wrong. Genre, intended reader, paper, printing method, trim, and the face's actual drawing matter more than a label.
Inspect the entire family and character set
A book needs more than regular letters. Compare the italic as a real companion rather than an electronically slanted roman, check bold and semibold hierarchy, and look for small caps when the design uses them. Inspect quotation marks, apostrophes, dashes, ellipses, currency, fractions, numerals, footnote symbols, accented characters, and every language the text contains.
Missing glyphs can trigger fallback fonts that are visible only in a few names or references. Search the final PDF font list for unexpected families and test the EPUB on multiple reading systems. Do not use a decorative display face for body copy merely because it matches the cover.
Tune size, leading, and measure together
Point size does not equal perceived size. A face with a large x-height can look bigger than another at the same nominal setting, while narrow letters fit more characters on a line. Start with a comfortable body size for the audience and trim, then adjust leading so lines separate without becoming disconnected.
Watch the average line length and paragraph color across full pages. Long dense lines need more room; very short lines can create uneven spacing and constant hyphenation. Margins define the measure, so changing the font or trim can require a new page frame rather than a simple size adjustment.
Check licensing and embedding before committing
A font being installed on a computer or free to download does not prove that it can be embedded in commercial print and ebook files. Read the current license for desktop use, PDF embedding, ebook distribution, modifications, and collaborators. Keep the license record with the production files.
Export a representative PDF and verify embedding before typesetting the whole book. Build a test EPUB if the same family will be embedded there, because ebook licensing and file-size limits may differ. System fonts and open-licensed families can simplify the workflow, but their exact terms still need review.
Proof on paper and in the ebook
Print several candidate spreads at actual size on paper similar in color to the final stock. Compare body texture, weight, punctuation, italics, small type, and show-through. A face that looks light and refined on screen may reproduce weakly; another can fill in on absorbent paper or at a small size.
For a reflowable ebook, assume readers may replace the publisher font. Preserve semantic hierarchy and test the book with the embedded face, a common reader serif, a sans serif, large text, and narrow screens. The design succeeds when the content remains navigable and intelligible after user preferences override its styling.
Sources: Amazon KDP: Paperback submission guidelines · Amazon KDP: Convert a paperback Word file to PDF · W3C: EPUB 3.3. Reviewed ; recheck current platform requirements before production.