"The suspension of such colours in the egg medium and laid over a gesso or gilt-gesso ground,
allowed the light to pass through the materials and be reflected into the eye in a series of events that are almost alchemical in that they demonstrate a transformation of matter, or rather,of vibrations of light. The transformation of matter by the finer vibrations of light can be regarded as more than the ultimate spiritual symbol: it is a demonstration of actions of divine energy manifested on the physical plane."