Design Nomenclature / Type
Mean line
Also called x-line, waist line, midline
- Type
- 2D
The line touching the tops of the flat lowercase letters — x, v, z — with round letters like o and e overshooting it. The distance from the baseline to it is the x-height. Ascending letters pass through it; the shoulders of n, m and h spring from just below it.
Not to be confused with
- BaselineThe invisible line on which the flat-bottomed letters of a line of text sit and from which vertical metrics are measured. Round and pointed letters drop below it by design. In digital fonts it is the y-origin of the glyph coordinate system, which makes it the anchor for alignment across mixed sizes and mixed scripts.
- X-heightThe height of the lowercase x — flat-topped and flat-bottomed, so it measures cleanly — taken from the baseline to the mean line. It is the best single predictor of how large a face reads at a given point size, and the ratio of x-height to cap height largely sets a face's apparent scale and small-size legibility.