Design Nomenclature / Type
Baseline grid
Also called vertical rhythm, baseline rhythm
An invisible ruling at a fixed interval to which every baseline in a layout snaps, so text in adjacent columns aligns line for line and headings, images and rules land on the same increments. On the web it is enforced by making every vertical measurement a multiple of the body line-height rather than by an actual grid.
In practice
Vertical rhythm is the web's name for the same idea, and it is the first thing to break: one image of arbitrary height, or one user font-size override, and the whole column drifts off. Worth doing where content is controlled, not worth bleeding for elsewhere.
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.
- GridA structure of repeated divisions — columns, rows, gutters, margins — fixing where elements may start and stop. Its value is decisional rather than aesthetic: it turns each placement from a judgment into a lookup, so a body of pages holds together across time and across hands.