1901 / Indanthrene
René Bohn (1862–1922) discovers a new blue dye in 1901. Indanthrene Blue RS surpasses indigo in colorfastness and lightfastness. The resulting high-quality indanthrene vat dyes (water-insoluble textile dyes) lead to new application opportunities in textile dyeing and printing.
The introduction of indigo and indanthrene in the practice is decisively promoted by the reduction and vatting agent “Hydrosulfite Conc. BASF” and Rongalit which convert the dyes into a water-soluble form during the dyeing process.