Trim size
Trim size is the finished width × height of a printed book's pages — 6×9 in is the most common self-publishing trim. Your interior PDF's pages must match the trim exactly.
Full definition →Reference
Glossary
Plain-English definitions of the typesetting and book-design terms behind a professional book interior — from trim size and gutter to running heads, drop caps, and front matter. Open any term for the full definition and related tools.
Gutter
The gutter is the extra inside margin next to a book's spine, added because binding swallows part of the page. Required gutter grows with page count — on KDP from 0.375" (≤150 pages) to 0.875" (828 pages).
Full definition →Recto and verso
Recto is the right-hand page of an open book (odd page numbers); verso is the left (even). Trade convention opens chapters on the recto, inserting a blank verso when needed.
Full definition →Running head
A running head is the line of text at the top of a book page — conventionally the author's name on the verso (left) and the book or chapter title on the recto (right). It is omitted on chapter openers and blank pages.
Full definition →Drop cap
A drop cap is an enlarged first letter that 'drops' into the opening lines of a chapter — typically 2–3 lines tall — signaling a beginning with typographic ceremony.
Full definition →Folio
In book design, the folio is the printed page number. A 'drop folio' sits at the foot of the page — the convention for chapter openers even when other pages carry numbers in the running head.
Full definition →Scene break
A scene break is a visual pause inside a chapter — marked in manuscripts as *** or a blank-line gap, and typeset as white space or an ornament (❦, ⁂, · · ·) with the next paragraph unindented.
Full definition →Widows and orphans
A widow is a paragraph's last line stranded at the top of a page; an orphan is a first line left alone at the bottom. Professional typesetting prevents both by adjusting page breaks.
Full definition →EPUB
EPUB is the open ebook format accepted by every major store — Amazon KDP, Apple Books, Kobo. A valid EPUB3 contains per-chapter files, a navigation table of contents, and metadata.
Full definition →Bleed
Bleed is printing past the trim line (usually 0.125") so ink reaches the page edge after trimming. Text-only book interiors don't need bleed; full-page images do.
Full definition →Front matter
Front matter is everything before chapter one: title page, copyright page, dedication, epigraph, table of contents. It is numbered separately by convention (roman numerals) and typically adds 4–8 pages to a book.
Full definition →Leading
Leading (rhymes with 'sledding') is the vertical space between lines of type, named for the lead strips typesetters once inserted. Book body text is usually set with leading around 120–145% of the font size — 11pt type on 13–14pt leading is a common novel setting.
Full definition →Half-title
The half-title is the first printed page of a traditional book: a right-hand page carrying only the book's title — no author, no publisher. The full title page follows a leaf later.
Full definition →Imprint page
The imprint page (copyright page) is the verso of the title page carrying the book's legal and bibliographic details: copyright notice, ISBN, edition, publisher or 'independently published', and any legal disclaimers.
Full definition →Kerning
Kerning is the adjustment of space between two specific letters, so pairs like AV or To do not leave a visible gap. It is a per-pair fix, not a setting you apply to a whole paragraph.
Full definition →Tracking
Tracking is uniform letter-spacing applied across a run of text, unlike kerning which adjusts one pair. Small negative tracking can pull a stubborn widow back onto the previous line.
Full definition →Ligature
A ligature is a single glyph replacing two or more letters that would otherwise collide — most commonly fi, fl, ff, ffi and ffl. Good book typography leaves standard ligatures on.
Full definition →Justification
Justified text is flush on both the left and right margins, achieved by varying word spacing. Most printed novels are justified; most ebooks are better left ragged right.
Full definition →Hyphenation
Hyphenation breaks long words across lines at syllable boundaries so justified text keeps even spacing. Justification without hyphenation is the main cause of ugly gaps in a printed page.
Full definition →Rag
The rag is the uneven edge of unjustified text — the right edge in left-aligned setting. A good rag is shallow and irregular; a bad one forms shapes, wedges or near-straight runs.
Full definition →River
A river is an accidental channel of white space running down several lines of a paragraph, caused by word spaces stacking vertically. Rivers appear in justified text with wide spacing.
Full definition →Small caps
Small caps are capital letters drawn at roughly the height of a lowercase x, used for acronyms and chapter openings. True small caps are cut by the type designer; fake ones are shrunk capitals.
Full definition →Em dash
An em dash (—) is a dash the width of the type size, used to mark a break in a sentence or an interrupted line of dialogue. It is the longest of the three horizontal marks.
Full definition →En dash
An en dash (–) is half the width of an em dash and marks ranges — 1939–45, pp. 22–30 — and compound relationships such as a London–Paris flight. It is not a hyphen.
Full definition →Point size
Point size is the nominal size of type, measured in points of 1/72 inch. Book body text is usually 10–12 pt, but two faces at the same point size can look noticeably different in size.
Full definition →Pica
A pica is a printing unit equal to 12 points, or 1/6 inch. Page measures and margins are traditionally specified in picas — a 27-pica measure is 4.5 inches.
Full definition →Typeface vs font
A typeface is the design — Garamond. A font is one specific instance of it — Garamond Italic at 11 pt. In everyday software the two words have merged, but in print specification the distinction still does real work.
Full definition →Serif
A serif is the small finishing stroke at the end of a letter's stem, and a serif typeface is one that has them. Printed book interiors are overwhelmingly set in serif faces.
Full definition →Sans serif
A sans serif typeface has no finishing strokes on its letters. In books it is normally reserved for headings, captions and technical matter rather than long passages of body text.
Full definition →Back matter
Back matter is everything after the main text: acknowledgements, appendices, notes, bibliography, index, about-the-author and any call to action. It is where an indie book earns its next reader.
Full definition →Colophon
A colophon is a short note, usually on the last page, recording how the book was made — the typeface used, sometimes the paper, press or designer. It is optional and quietly signals craft.
Full definition →Copyright page
The copyright page carries the copyright notice, edition, ISBN, publisher imprint and legal disclaimers. It sits on the verso immediately after the title page.
Full definition →Epigraph
An epigraph is a short quotation placed at the start of a book, part or chapter to set its tone. It is typically set smaller than body text, ranged left or centred, with the source beneath.
Full definition →Frontispiece
A frontispiece is an illustration facing the title page, on the verso opposite. It is the one image many otherwise text-only books carry.
Full definition →Spine
The spine is the bound edge of the book, carrying the title, author and imprint. Its width is calculated from page count and paper thickness, so it can only be finalised after the interior is typeset.
Full definition →Endpapers
Endpapers are the heavier sheets glued between a hardback's cover boards and its text block, one at each end. Paperbacks and most print-on-demand hardbacks do not have them.
Full definition →Dust jacket
A dust jacket is the printed paper wrapper folded around a hardback, with flaps carrying the blurb and author biography. The case underneath is usually plain cloth or board.
Full definition →Perfect binding
Perfect binding glues the trimmed page edges into a wrap-around cover, producing the standard flat-spined paperback. It is what every print-on-demand paperback uses.
Full definition →Saddle stitch
Saddle stitching folds nested sheets and staples them through the spine fold. It suits booklets up to roughly 48–64 pages and produces no flat spine to print on.
Full definition →Case binding
Case binding sews or glues the text block and attaches it to rigid boards covered in cloth, paper or laminate — the construction of a hardback. Print-on-demand hardbacks are usually case-laminate.
Full definition →Signature
A signature is a large printed sheet folded into a group of pages — commonly 16 or 32 — that is then bound with others. It is why traditionally printed books run to page counts in multiples of 16.
Full definition →ISBN
An ISBN is the 13-digit International Standard Book Number identifying one edition of one book in one format. A paperback, a hardback and an ebook each need their own.
Full definition →Print on demand
Print on demand manufactures a copy only once it is ordered, removing inventory and minimum print runs. It is how most self-published paperbacks reach readers.
Full definition →Reflowable vs fixed layout
Reflowable ebooks let text re-wrap to the device and reader's font size; fixed-layout ebooks preserve an exact page design. Novels should be reflowable; only image-led books need fixed layout.
Full definition →Galley proof
A galley proof is an early typeset version circulated for correction and review before final pages are set. The name survives from the metal trays that held type before it was made up into pages.
Full definition →Proof copy
A proof copy is a physical copy printed from the final files and checked before the book goes on sale. It is the only reliable way to judge margins, gutter and print colour.
Full definition →CMYK vs RGB
RGB is the additive colour of screens; CMYK is the subtractive ink model of printing. Covers are printed in CMYK, so bright screen colours reliably print duller than they look.
Full definition →DPI vs PPI
PPI is the pixel density of an image file; DPI is the dot density a printer lays down. Print work asks for 300 PPI at final printed size — an image's pixel count only means something once you fix how large it will print.
Full definition →Typesetting
Typesetting is arranging text into finished pages — choosing the face, size, leading and measure, then resolving every page break, widow and orphan. It is the step between an edited manuscript and a printable book.
Full definition →Manuscript format
Manuscript format is the plain submission layout — double-spaced, 12 pt, one-inch margins, indented paragraphs, no styling. It is deliberately not book design, and it is not what a reader should ever see.
Full definition →Chapter opener
The chapter opener is the first page of a chapter, set with a sink of white space above the title and often a drop cap or small caps on the first line. It is the strongest design signal in a book interior.
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