Kernwick Type

Type on a page holds together when its sizes come from one decision rather than seven. Kernwick Type is a specimen sheet for that decision: set a base size, choose a ratio, and read the scale that falls out of them.

The scale

Eight ratios, from a close Minor Second up to the Golden — the intervals typographers borrowed from music. Kernwick works the steps from −2 to +6, each with its computed size, a suggested line-height that tightens as the size grows, and the rounded value you would actually ship. Every step sets a live "Ag" at its exact size, so the scale is something you look at rather than a column of figures. Read it in sp, in px at a density you pick, or in rem against a 16 base.

The grid

Give it a container width, a column count, a gutter and an outer margin. Kernwick returns the exact column width, the content width, and the space the gutters take between them, and draws the columns to scale beneath the numbers. Ask for more columns than the width can carry and it says so plainly rather than handing back a negative figure. The baseline check then measures each line-height against a 4 or 8 dp step and names the ones that drift.

The specimen

The whole scale, set as a page: a display line, four headings, body copy and a caption, each at its own step and line-height. Turn the page from a serif to a sans and watch the rhythm shift under it. A measure readout counts the characters falling on a line of body copy and tells you where that sits against the 45–75 most readers settle into.

Set once

Base, ratio, unit, grid and face are all remembered, so the app opens on the page you left.

Kernwick Type is quiet on purpose — paper, ink, one vermilion accent, and nothing on screen that asks for attention it hasn't earned.