Painters BLUE is made different according to the different kinds of painting. In limning, fresco, and miniature, they use indifferently ultramarine, blue-ashes, and smalt: These are their natural blues, excepting the last, which is partly natural, and partly artificial.
In oil and miniature, they also use indigo prepared; as also a fictitious ultramarine. See ULTRAMARINE and INDIGO.
Enamellers, and painters upon glass, have also blues proper to themselves, each preparing them after their own manner.