Weight

The relative thickness of a
Typeface
Stroke
, expressed as a named grade within the
Type Family
range. The scale extends from Thin or Hairline at the lightest extreme through Light, Regular (also called Book or
Roman
), Medium, Semibold, Bold, Extra Bold, to Black or Heavy at the heaviest. Weight is the primary axis of variation within a type family and the most common tool for establishing typographic
Hierarchy
. In digital font technology, weights are often mapped to numeric values on a 1–999 scale (
CSS
and
OpenType
use 100–900 in increments of 100 by convention, with 400 = Regular and 700 = Bold).