Density

What density is

Density is the proportion of a Vaquum surface occupied by mark, measured against the surface area as a whole. Three values close the parameter: sparse, moderate, dense. Each value names a bracket on a single continuous axis — mark coverage as a percentage of pixel area. The exhibit below renders the three brackets read directly from @vaquum/face/parameters/density, with the failure region beyond 15 percent shown explicitly.

Three values

A sparse surface keeps mark coverage at or below 6 percent of pixels and reads as predominantly whitespace at the canonical viewing distance. A moderate surface sits between 6 and 12 percent, the bracket that carries argument, exhibit, and quantitative table on one page. A dense surface ranges from 12 to 15 percent — the upper bound of the parameter. Dense surfaces serve ledgers, dashboards, and tabular dense-app contexts where the reading task is scanning rather than passage reading.

The 15 percent ceiling

Above 15 percent mark coverage the surface earns a composition failure. The whitespace the system depends on for hierarchy and proximity grouping no longer carries structural work. The validator measures coverage by pixel counting after render. The rule lives in the @vaquum/surface/composition rule list under stage rendered, runs as part of pnpm validate:composition, and emits a fail the moment the threshold is crossed.

How density composes with rhythm

Density names a static target — how much mark per unit of space. Rhythm names how predictably that mark recurs across the surface. A surface that declares density: sparse with rhythm: arrhythmic earns a composition failure on the rhythm axis even where its coverage falls within bounds. The parameters are independent, and each must hold on its own. The closed sets compose without contradiction at every permitted combination.