![]() During the 217-day Siege of Mafeking of the town of Mafeking ( Mafikeng) in South Africa during the Second Boer War from October 1899, the process was used to print stamps and banknotes. In this application and with the manufacture of blueprint papers, it remained the dominant reprographic process until the 1940s. Marion and Company of Paris were first to market the cyanotype, under the proprietary name of “Ferro-prussiate,” for reprography of plans and technical drawings and to advantage due to its low cost and simplicity of processing which required only water. Ĭommercial use came only in 1872, the year after Herschel's death. The latter in making fine presentation albums of bridges and structural steel, foresaw an appropriate effect in colour: the intense blues of his refined cyanotypes from large glass plates were printed on fine French paper 37 cm x 43.6 cm, watermarked Johannot et Cie. The medium was immediately taken up and perfected by notable photographic practitioners of the time, including William Henry Fox Talbot and Henry Bosse. quickly disseminated information on the new medium internationally in his popular 1843 fifty-page manual Photogenic manipulation, containing plain instructions in the theory and practice of the arts of photography: calotype, cyanotype, ferrotype, chrysotype, anthotype, daguerreotype, and thermography, which the following year was translated into German and Dutch. Īs with all of his photographic inventions, Herschel did not patent his cyanotype process. John Mercer in the 1850s used the process for printing photographs onto cotton textiles and discovered means of toning the cyanotype violet, green, brown, red, or black. Also in the Antipodes, Herbert Dobbie in imitation of Atkins produced a book New Zealand ferns: 148 varieties, but with double-sided pages of cyanotype prints, in 1880. After the Ross Antarctic Expedition (1839–1843) John Davis, artist and naturalist on the expedition, made or commissioned some cyanotypes in 1848 from seaweeds collected on the voyage. ![]() Intensifying and fixing is achieved simply by rinsing the print in water in which unexposed sensitizer and reaction products are readily soluble.Īnna Atkins, a friend of the Herschel family, over 1843–61 and with the assistance of Anne Dixon, hand-printed several albums of botanical and textile specimens, especially Photographs of British Algae: Cyanotype Impressions, effectively the world’s first photographically-illustrated books. Exposed to sunlight, the ferric salt is reduced then combines with the ferricyanide to yield ferric ferrocyanide Prussian blue (also known as Turnbull’s blue, or Berlin Blue in Germany). He mixed the ammonium ferric citrate in a 20% aqueous solution, with 16% of the potassium ferricyanide, to make the sensitizer for coating plain paper. Īlfred Smee had in 1840 used electrochemistry to isolate a pure form of potassium ferricyanide, which he sent to Herschel whose innovation was to use the ammonium iron(III) citrate or tartrate, then commercially available as an iron tonic and also introduced to him by Smee, for photographic purpose. ![]() Though Döbereiner had published in 1831 in German on the light-sensitivity of ferric oxalate, of which Herschel became aware during his visit to Hamburg, it is too lightly toned to form a satisfactory image and would require a second reaction to make a permanent print. The cyanotype was discovered, and named thus, by Sir John Herschel who in 1842 published his investigation of light on iron compounds, expecting that photochemical reactions would reveal, in form visible to the human eye, the infrared extreme of the electromagnetic spectrum detected by his father and the ultra-violet or ‘ actinic’ rays that had been discovered in 1801 by Johann Ritter. ![]()
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