Specimen.

The typeface is an instrument. The astrolabe encoded the celestial sphere in geometry. The typeface encodes language in geometry. Every letterform is a path; every weight is a parameter; every italic is a slant transform. The specimen sheet is the editorial register that five hundred years of foundries have used to demonstrate what their typefaces can do — set the letter at full size, set it again smaller, set it on the page where the proportions speak for themselves.

Claude Garamond cut his first roman typeface in Paris in the 1530s; by 1545 he was selling matrices across the French printing trade. His romans set the European standard for two centuries — the proportions, the spacing, the colour on the page. Garamond's roman is the typeface every revival since has tried to find again. The book the eye stops noticing is set in something Garamond would recognise.

A century and a half later, William Caslon worked from his foundry on Chiswell Street in London. He cut a roman of his own — sturdier than Garamond, more open, designed for the English language and the English book trade. The 1776 Declaration of Independence was set in Caslon. So was nearly every 18th-century English book. The phrase when in doubt, use Caslon was practical advice for two hundred years.

Bodoni worked at the court of Parma at the end of the 18th century. He cut a roman with extreme contrast — hairline thins, square serifs, mathematical geometry. The first modern typeface in the technical sense: the contrast and the geometry of Bodoni defined what every type designer after him would react against. Fashion magazines still set their nameplates in faces descended from his.

Metal type became photo type, then digital, then variable. The matrices became drawings, then bezier curves, then variation axes. What didn't change is the discipline: every letterform is a path, every weight a parameter, every italic a slant transform. The specimen sheet still has the same job — show the type at full size, show it small, show what it does on the page.