For reference, here's all three of those dyes next to each other, on the same wool tapestry [0,1]—and also the black made by mixing them together. Says [2]: "Bl

For reference, here's all three of those dyes next to each other, on the same wool tapestry [0,1]—and also the black made by mixing them together. Says [2]: "Blue and black are the most stable dyes; the bright blue sky, woven with indigotin-containing dye (probably woad), has barely faded over the centuries. To achieve brown or black, a combination of madder, weld, and an indigotin-containing dye such as woad was used." [0] https://www.metmuseum.org/art/collection/search/467654 https://www.metmuseum.org/art/collection/search/467654 ("The Unicorn Surrenders to a Maiden (from the Unicorn Tapestries)") [1] https://en.wikipedia.org/wiki/The_Unicorn_Tapestries https://en.wikipedia.org/wiki/The_Unicorn_Tapestries [2] https://sci-hub.se/10.1086/met.45.41558055 https://sci-hub.se/10.1086/met.45.41558055 ("Three Fragments of the “Mystic Capture of the Unicorn” Tapestry") edit: Here's an article [3] about the digitization story of these tapestries (presumably what's used in that hi-res zoomable image in [0]): "“It took us three months of computation,” Gregory said. “We should have just dropped it.”" [3] https://www.newyorker.com/magazine/2005/04/11/capturing-the-unicorn https://www.newyorker.com/magazine/2005/04/11/capturing-the-... ("Capturing the Unicorn")