In 1843 the botanist Anna Atkins began issuing "Photographs of British Algae: Cyanotype Impressions" — the first book illustrated with photographs. She laid dried seaweed onto paper sensitized with Herschel's iron-salt chemistry; where the specimen blocked the sun, the page stayed white, and everywhere else the paper oxidized to deep Prussian blue.

This system rebuilds that contact-print logic. The ground is always the saturated ferrous blue of exposed cyanotype paper; the highlight is the bare white silhouette of a specimen. Old-style serif book faces and generous botanical-plate margins carry the scientific gravity of a Victorian folio.