“The Cat” dye mill: https://www.verfmolendekat.com/en/ in Zaanse Schans, Netherlands.
An oblique history of dye because the first chemical ones were literally deadly: “The Poisoner’s Handbook” by Deborah Blum. Her other book on the history of the FDA is “The Poison Squad” (do you see a trend). Anyway, it turns out the wife of the guy who essentially created the FDA was freaking awesome. It is non-fiction books like these that made me give up on fiction.