For centuries, Jan van Eyck was credited as the inventor of oil painting. While modern research shows that oil-based pigments existed much earlier (even in ancient Afghan cave paintings), Van Eyck was the first to perfect the medium. By mixing pigments with linseed or walnut oil, he created 'glazes'—thin, transparent layers that allowed light to pass through and reflect off the white base of the panel. This created a level of depth, realism, and vibrant color that was impossible with 'egg tempera.' His 1434 work 'The Arnolfini Portrait' is a masterclass in this technique, featuring microscopic details like a reflection of the artist in a convex mirror. His 'Northern Renaissance' style revolutionized European art, leading to the dominance of oil on canvas.