Typography that reads well
Choosing a font is the small decision. Size, line height and line length are the big ones. Learn the numbers that make text comfortable, how to pair typefaces, and what changes in Persian.
Serif and sans-serif
Serif
Letters with small strokes at the ends, like the ones on a printed book page or a newspaper masthead. Feels traditional, literary, official. Good for long printed text and for anything that wants to sound established.
Sans-serif
No end strokes; plain, even shapes. Feels modern, neutral, technical. Good for screens, signs, small sizes and interfaces. Most apps and most road signs are sans.
What actually decides readability
- Size. Body text around 10–12pt in print, around 16px on screen, 24pt or more on a slide. Then ask where it will really be read: from the back row, on a wall, on a phone in sunlight.
- Line height. About 1.4 to 1.6 times the size for body text. Tighter for big headings.
- Line length. Roughly 45 to 75 characters a line.
- Alignment. Align to the side where reading starts and leave the far edge ragged, as in lesson 3. Justified text on short lines opens ugly rivers of white space.
- Which typeface. Last, and the least important. Almost every well-known family you already have is good enough for the work you're doing.
Check yourself
Omid writes a one-page notice on A4 at 11pt, running the full width of the page with narrow margins. Readers say it is tiring even though the words are short. Which change helps most?
- Make the text smaller so the page holds it more comfortably
- Narrow the text to about 45 to 75 characters a line
- Centre every paragraph so the page looks balanced
- Switch to a more decorative typeface with more character
Show the answer
Narrow the text to about 45 to 75 characters a line
Right. Full-width A4 at 11pt runs well past 80 characters, and the eye keeps losing its place returning to the start of the next line. Wider margins or two columns fix it without touching a word.
Line height
The distance from one line of text down to the next, usually written as a multiple of the font size. 1.0 means the lines almost touch. Body text reads best at about 1.4 to 1.6. Large headings need less, roughly 1.1 to 1.2, because at a big size the same multiple opens into a hole.
16px text at 1.5 puts 24px between one line and the next. Drop the same paragraph to 1.1 and it turns into a grey brick your eye slides off.
Line length
How many characters fit on one line, spaces counted. Comfortable reading sits at roughly 45 to 75 characters, with about 60 in the middle of that range. Too long, and the eye loses its place on the journey back to the start of the next line. Too short, and the sentence arrives in fragments and you read in jerks.
A paragraph running the full width of a wide laptop screen can reach 130 characters. That is why the same article often feels easier on a phone, where the column is narrow whether the designer thought about it or not.
A body-text recipe
where size line height line length
printed A4 10-12 pt 1.4-1.5 x 45-75 characters
a web page 16 px 1.5-1.6 x 45-75 characters
a phone 16 px 1.5-1.6 x 35-50 characters
a slide 24 pt + 1.2-1.3 x one short line
Working out an A4 page:
page width 21 cm
margins 3 cm each side -> text column 15 cm
at 11 pt that is roughly 80+ characters: still too wide
margins 4 cm each side -> text column 13 cm
roughly 65 characters: rightWide margins are not decoration.
They are how you set the line length.If you can't change the margins, use two columns, or raise the text size: bigger letters mean fewer characters per line.
Check yourself
Negar sets her body text at 1.5 line height and her 48pt heading at 1.15. Two different numbers is the consistent choice here, not a slip.
Show the answer
True
True. Line height is a multiple of the text size, so the bigger the type the more space each step adds. Body text is comfortable at about 1.4 to 1.6, but a 48pt heading at 1.5 opens a visible hole between its lines; about 1.1 to 1.2 keeps it tight. Consistency means applying one rule everywhere, not one number.
PAIRING
Two typefaces at most
Two is the ceiling, and one is often better. The safest pairing isn't two typefaces at all: it is one family in two weights, bold for headings and regular for body. If you do want two, make them clearly unlike, because lesson 2's rule about timid contrast applies to type as well. A serif for headings with a sans for body is the classic pair, and it works because nobody could confuse the two.
A café menu set in one family: section names in bold, dish names in regular, prices in the same regular. One typeface doing three jobs, and nothing on the page can clash.
Check yourself
Match each setting to the number that usually works
Show the answer
- Line height for body text → About 1.4 to 1.6 times the size
- Line height for a large heading → About 1.1 to 1.2 times the size
- Line length for comfortable reading → About 45 to 75 characters
- Number of typefaces on one page → Two, and often one is better
Check yourself
Does this help reading or hurt it?
- Body text set at 1.5 line height
- A whole paragraph set in capitals
- Headings in the bold weight of the body font
- Four typefaces on one poster
- Lines running the full width of a wide screen
- A text column narrowed to about 60 characters
Show the answer
Helps: Body text set at 1.5 line height, Headings in the bold weight of the body font, A text column narrowed to about 60 characters
Hurts: A whole paragraph set in capitals, Four typefaces on one poster, Lines running the full width of a wide screen
Check yourself
Negar is making a Persian poster from a template built for English. To make the title stand out she adds letter-spacing and slants the Persian text into italic. What is wrong?
- Letter-spacing breaks the joined script and the slant distorts the letterforms
- Nothing is wrong; both are normal ways to make a title stand out in any language
- The title also needs to be centred for the poster to look balanced
- Persian titles should always be set in a serif typeface
Show the answer
Letter-spacing breaks the joined script and the slant distorts the letterforms
Right. Persian letters connect, so spacing them apart splits words into pieces, and most Persian fonts have no true italic, so the tool just skews them. Use size, weight and colour instead, with a family that has real weights.
Lesson recap
- Serif feels traditional and suits long printed text; sans feels modern and suits screens, signs and small sizes.
- Body text: about 16px on screen or 10–12pt in print, line height 1.4–1.6, lines of 45–75 characters.
- Big headings take a tighter line height, about 1.1–1.2.
- Two typefaces at most, and one family in two weights is safer than two families.
- Persian needs a real Persian font, more line height (about 1.7–2.0), no letter-spacing, no all-caps and no fake italic.