It’s Chrome Black T. Why is it called Chrome Black T? It doesn’t contain chromium and it’s not black! I checked the English name, and it’s even weirder. After translation, it’s called Wool Chrome Black T, which is related to wool again! Please

I am interested in any questions related to naming, haha. Eriochrome is a registered trademark of the Swiss chemical company Ciba-Geigy (one of the predecessors of today's Novartis), which is a combination of erio- (ancient Greek meaning "wool") and chrome (chromium) , used as the brand name for a series of chromium mordant dyes developed by the company and suitable for dyeing wool products. The so-called "chromium mordant dyes" are dyes using dichromate as mordant. Many synthetic dye molecules cannot be directly combined with fabric molecules and must be firmly attached to fabric molecules through another chemical substance as a medium. These chemical substances as medium are mordants. For wool, dichromate is a good mordant. As for it itself is not black, but it is called "chrome black", maybe it is because the solid state is brown-black, or it is dyed black after being combined with chromium and dyed on the wool? To be tested.