Leading is the vertical space that separates two lines of text, usually measured from one baseline to the next. Inherited from metal type printing, where thin strips of lead were slipped between the lines, it shapes the breathing room and readability of a text.
Where to see it
Leading is set in every layout application, often written as “10/12” for 10-point text on 12 points of leading. On the web, it corresponds to the CSS line-height property, usually set between 1.4 and 1.6 times the point size for body text.
Why this detail matters
Adjusting the leading profoundly changes the reading experience and look of a text:
- Leading that is too tight makes ascenders and descenders touch and makes lines hard to follow;
- Leading that is too loose scatters the text, which loses its cohesion and gives the impression of floating lines;
- It must adapt to the point size, the line length and the typeface: long lines or a large x-height often need more air.
Related term
Point size is the size of a typeface expressed in points; leading is always set in relation to it.