In our modern world it’s easy to take colour for granted. Yet before organic chemistry the most desirable pigments were often exotic or poisonous.
Merchants supplied pungent yellow ‘purree’ nuggets from India, cochineal ‘grana’ from the holds of Spanish galleons, lapis rock carried by camel train from the mountains of Badakhshan. Alchemists prepared deadly ‘King’s Yellow’ and ‘Ruby of Arsenic’. ‘Moorish Gold’ was concocted, according to a 12th century monk, from basilisk powder ground with human blood!
Small wonder artists kept their paint recipes closely guarded in Books of Secrets.