Titre : Prussian blue, such a French dye Auteurs : François Delamare, Revue : Technology and Innovation Numéro : Issue 4 Volume : 4 Date : 2019/09/12 DOI : 10.21494/ISTE.OP.2019.0408 ISSN : 2399-8571 Résumé : While Prussian blue did indeed begin its European career as a pigment, it was as a dye that it spread in France during the 19th Century. As early as the 18th century, various French chemists (Macquer, Le Pileur d’Apligny) had foreseen and proved that Prussian blue could be used as a dye. This discovery did not interest French dyers, who at that time used indigo from the French Antilles which was very cheap. It wasn’t until the break in international trade due to the Continental System (1806) that the French government urgently began to seek a replacement blue. J.-M. Raymond perfected the Prussian blue dyeing of silk (Raymond blue) in 1811 and his son, P. Raymond, that of wool cloth in 1822. The shades obtained were so highly prized that these dyes would be retained after the Empire’s fall, when France would again import indigo, English this time, from the Carolinas. The fashion in France for Prussian blue dyeing was then the cause for the development of an industry for the production of cyanides and yellow potash prussiate, the major part of which was used for dyeing. Manufacturing processes evolved but this flourishing situation was brutally brought to an end in the 1860s by the appearance of the first blue aniline dyes. Éditeur : ISTE OpenScience