This is an occupation known as painting, which calls for imagination, and skill of hand, in order to discover things not seen, hiding themselves under the shadow of natural objects, and to fix them with the hand, presenting to plain sight what does not actually exist.
Cennino CenniniIn the first place you must study drawing for at least one year; then you must remain with a master at the workshop for the space of six years at least , that you may learn all the parts and members of the art...drawing without intermission on holidays and work-days
Cennino Cennini