In light of Jo & Marika's essay, the editorial comment on fol. 11r_1 should be changed from
Cendre (ash), fleur (flower), and le plus subtil (the subtlest part) are grades of a blue pigment, likely azurite or perhaps smalt. See Spring and Kirby, "Ms. Fr. 640 in the World of Pigments in sixteenth-century Europe," https://edition640.makingandknowing.org/#/essays/ann321ie19. TO Cendre (ash), fleur (flower), and le plus subtil (the subtlest part) are grades of a blue pigment, such as azurite or, as is most likely here, smalt. See Spring and Kirby, "Ms. Fr. 640 in the World of Pigments in Sixteenth-Century Europe," https://edition640.makingandknowing.org/#/essays/ann321ie19.
done