Leading
Also called Line spacing, Line height
The distance from one baseline to the next, named after the strips of lead once slid between lines of metal type.
Near it
Baseline
Measure
Ascender
Baseline grid
DescenderWhat it is made of
| set solid | leading equal to the type size | too tight for most text faces |
| normal text | roughly 1.2 to 1.6 times the size | longer measures want more |
| the relation that matters | leading and measure move together | a long line needs more leading or the eye returns to the wrong one |