Typography has a reputation for being a matter of taste, and at the top end it is. At the level that separates a book someone will read from one they will put down, it is closer to a checklist. Here is the checklist.
1. Line length is the one that matters most
The measure is how many characters fit on a line. Too long and the eye loses its place travelling back to the start; too short and the reading rhythm breaks every few words.
Aim for 60 to 75 characters per line, counting spaces. This is the single most reliable number in typography and it has held across centuries of book design.
You do not control it directly — it falls out of page width, margins and type size. To measure it, print a page and count the characters in a few full lines. If you are at 90, the fix is wider margins or larger type, not a different typeface.
2. Type size, in the context it will be read
10 to 12 point for body text in a printed book. Screen-only PDFs can carry a little more, 11 to 13. Below 9pt you are excluding readers; above 14 the page starts to feel like a large-print edition, which is a legitimate choice made deliberately and an accident otherwise.
Point size is not comparable between typefaces. Two faces at 11pt can differ noticeably in apparent size, because what varies is the x-height — the height of a lowercase 'x' relative to the capitals. Judge by looking at a printed page, not by the number.
3. Leading, which is line spacing
The space between baselines. In print it is quoted in points alongside the type size — "11 on 15" means 11pt type on 15pt baselines. On screen it tends to be a multiplier.
Around 1.4 times the type size is a safe default for body text. Denser than 1.2 and lines start to crowd; looser than 1.6 and paragraphs stop reading as blocks and start reading as stacks of separate lines.
Leading and measure interact: longer lines need more leading, because the eye has further to travel back and needs a clearer target. If you are stuck at a long measure for some reason, opening up the leading buys back some of the readability.
4. Margins are larger than you think
The instinct is to minimise margins, on the reasoning that white space is wasted paper. Every well-set book you have read disagrees.
Start at 20mm and go up. Traditional book margins run wider still, and are usually asymmetric — more room at the outside edge, where a thumb goes, and at the foot than the head. If you are printing and binding, the inner margin needs extra to account for the gutter, where the page curves into the spine.
Set margins in real units — points or millimetres — rather than as a percentage of the page. Percentages give you different physical margins on different page sizes, which is exactly what you do not want.
5. Two typefaces, three at the absolute most
A serif for body text and a companion for headings covers almost every book ever made. The classic pairing is a serif body with a sans-serif heading, and it is classic because it works: the contrast is obvious enough to signal hierarchy without looking accidental.
Pairings that hold up without much thought:
- A high-contrast serif for headings, a workhorse serif for body — Playfair Display with Lora, say. Elegant, slightly formal, good for fiction and memoir.
- Sans headings, serif body — Inter with Lora. Modern, clear, right for non-fiction and anything instructional.
- One family across both weights — a single face with a bold heading and regular body. Boring in the best sense, and impossible to get wrong.
The failure mode is mixing two faces that are almost the same. Two humanist sans-serifs at similar weights read as a mistake rather than a decision, because the reader cannot tell whether the difference was intended.
6. Hierarchy should be obvious at arm's length
Hold a page at arm's length so the words blur. You should still be able to see the structure — where sections begin, what is a heading, what is body. If everything greys into one texture, the hierarchy is too subtle.
Build it from a scale rather than picking sizes one at a time. Choose a ratio — 1.25 and 1.333 are both common — and multiply upward from your body size:
| Level | At 1.25 | Rounded |
|---|---|---|
| Body | 11pt | 11pt |
| Heading 3 | 11 × 1.25 | 14pt |
| Heading 2 | 14 × 1.25 | 17pt |
| Heading 1 | 17 × 1.25 | 21pt |
| Title | 21 × 1.25 | 27pt |
Sizes chosen from a ratio relate to each other visibly, which is most of what "looks designed" means. Sizes picked independently rarely do.
The order to work in
- Pick the page size — it constrains everything after it.
- Set margins generously, and check the resulting measure.
- Adjust type size until the measure lands between 60 and 75 characters.
- Set leading to about 1.4.
- Choose two typefaces, one for headings and one for body.
- Build the heading sizes from a ratio.
- Print a page. Actually print it. Screens lie about size and about contrast.
That last step is the one people skip and the one that catches the most. A page that looks generously spaced on a bright screen can look cramped on paper, and type that looked fine at 100% zoom can be a point too small in the hand.
In bukpress these are the controls, and deliberately not many more: three typefaces with their own sizes and colours, margins in points, line height, and the paper the text sits on. Pages are A4, so step one above is already decided for you. Saving the combination as a reusable Brand Kit — so the next book starts from decisions you have already checked — is on the Essentials plan and up. If you want to see the checklist applied, the sample book is eight pages of it.