Size and layout

The physical shape of your book — its trim size, margins, and typography — is set in document.yml under book:. Pick it once; every build uses it. This page explains the choices and how to make them.

Full field reference: book template. This page is the why behind the settings.

Trim size

The trim size is the finished page dimensions after the printer cuts the sheet. It's the single most defining physical choice — it sets how your book feels in the hand and constrains everything else. Set it with book.trim:

book:
  trim: trade-6x9

Built-in presets

Two more sizes exist for the article genre — full-size paper for documents and proofing copies rather than bound books:

A custom size

Any trim your printer supports. Give a width and height (and, if you like, margins) instead of a preset name:

book:
  trim:
    width: 5in       # a common "mass-market"-ish trade size
    height: 8in
    margins: { inside: 0.75in, outside: 0.5in, top: 0.75in, bottom: 0.75in }

You can also start from a preset and nudge one value:

book:
  trim:
    preset: trade-6x9
    margins: { inside: 0.9in }   # more gutter for a thick book

Pick a size your print-on-demand service offers. Each service lists its supported trim sizes; matching one avoids a custom-size surcharge. Check KDP's list or IngramSpark's.

Margins and the gutter

A bound book needs an asymmetric margin: the inside (gutter) edge — where the pages meet the spine — must be wider than the outside, or text disappears into the binding. The presets already do this. The four margins:

book:
  trim:
    preset: trade-6x9
    margins: { inside: 0.75in, outside: 0.5in, top: 0.75in, bottom: 0.75in }

The more pages, the more gutter you need — a thick book's spine "steals" more of the inside margin. Print-on-demand services publish a minimum inside margin by page count; a ~300-page 6×9 usually wants at least 0.75–0.875 in inside. Confirm against your service's table before you finalize, and widen inside if needed.

Bleed

Bleed is art that runs off the edge of the page. Because printers can't cut perfectly, anything meant to reach the edge must extend ~0.125 in past the trim, so the cut never leaves a white sliver.

• Text interiors need no bleed. Your words sit inside the margins; unipress emits pages at the exact trim size, which is exactly what print-on-demand wants for a text interior. This is the common case — you don't have to think about it.
• Full-bleed interior images (a photo running to the paper edge) are the exception. unipress emits trim-size pages, so it isn't set up for edge-to-edge interior art. Keep interior images within the text block, or ask your printer how they want full-bleed interior pages supplied.
• Your cover is where bleed really matters, and that's handled separately by your print service's cover template — see Covers and images.

Front matter

The pages before Chapter 1 — title, copyright, contents. Toggle them under book.structure:

book:
  structure:
    titlePage: true
    copyrightPage: true
    toc: true
    tocDepth: 2                 # how many heading levels the contents lists
    frontMatterNumbering: roman # none | roman | arabic

• titlePage — the title, subtitle, and author, typeset. If your cover art already carries the title (many do), you may want this off to avoid repeating it: titlePage: false.
• copyrightPage — the copyright/imprint page. Pulls from book.rights, book.publisher, book.isbn (see ISBNs and metadata).
• toc — a generated table of contents from your chapter titles.
• frontMatterNumbering: roman is the traditional convention: front matter is numbered i, ii, iii…; Chapter 1 resets to page 1. Use none to leave front matter unnumbered, or arabic to number straight through.

Typography

The defaults produce a clean, readable book — you can ship without touching them. When you want control, set it under book.typography:

book:
  typography:
    bodySize: 11pt
    leading: 0.72em          # line spacing
    firstLineIndent: 1.4em   # paragraph indent
    bodyFont: ["EB Garamond", "Georgia"]   # first available wins
    headingFont: ["EB Garamond", "Georgia"]

• Fonts are tried in order; the first one installed on the machine running the compile is used, and unipress embeds it in the PDF. Leave them unset to use the compiler's clean built-in defaults. If you name a font, make sure it's installed where you build.
• Body size and leading are the levers for page count and comfort. 10.5–11 pt with roomy leading reads well in a 6×9.
• For a classical look with these choices preconfigured, scaffold the monograph template instead of tuning by hand: unipress create my-book --template monograph.

Next

• Add your covers and images.
• Produce your ebook or go to print.