Cyanotype
1842–presentPrussian blue photography — iron-based process producing vivid blue images. Anna Atkins used it for the first photo-illustrated book.
Paper coated with iron salts (ferric ammonium citrate + potassium ferricyanide). UV exposure creates Prussian blue.
British
Invented by Herschel in 1842. Anna Atkins' botanical cyanotypes are the first photographs used for scientific illustration.
Iron-based, not silver. Prussian blue (ferric ferrocyanide) is the image substance. Architectural blueprints use the same chemistry.
Prussian blue deep
Maximum density — deep Prussian blue.
Material: Ferric ferrocyanide (Prussian blue), maximum density
RGB(10, 42, 90)
Cyanotype mid-blue
Medium blue — the characteristic cyanotype tone.
Material: Prussian blue, medium density
RGB(44, 90, 138)
Paper white (unexposed)
White of unexposed areas — bare paper washed clean.
Material: Rag paper, iron salts washed away
RGB(235, 224, 216)
Light blue wash
Pale blue of partially exposed areas.
Material: Prussian blue, low density
RGB(122, 170, 202)
Tea-toned brown
Brown variant when toned with tannic acid (tea/coffee).
Material: Prussian blue converted with tannin
RGB(91, 74, 58)
Botanical outline
The photogram edge where leaf meets blue background.
Material: Sharp edge between exposed and masked areas
RGB(28, 58, 106)
Pigments: Prussian blue
Related Materials
If this palette inspired you, here’s what to paint with.
Winsor & Newton Cotman Watercolour Studio Set, 24 Whole PansView on Amazon
Winsor & Newton Calligraphy Ink, Black, 30mlView on Amazon
Copic Ciao Alcohol Markers, Set of 6View on AmazonAs an Amazon Associate, Pigmentoria earns from qualifying purchases. This page may contain affiliate links.