"The gold of the ancient alchemists can actually be extracted from everything. But what is difficult is to discover the gift that is the philosopher's stone and that exists in each of us" (Y. Klein quoted in Yves Klein: A Retrospective, Nice, 2000).
Gold was part of Yves Klein's sacred triumvirate of colors, along with blue and rose. "All three live in one and the same state, each impregnated in the other, all being perfectly independent, one from the other" (Klein quoted in S. Stich, Yves Klein, Stuttgart, 1994, p. 194). In 1959, the year MG 20 was created, Klein extended his monochrome painting to include gold panels. This was not just a change of color but an expansion of Klein's ideas concerning the immaterial. Whereas blue was for Klein a color of deep spiritual resonance immersed in a sense of the infinite and evocative of the Void, gold was a symbol of timeless purity, of both materiality and its opposite-- the immaterial. Klein was well aware of the philosophical implication of gold for the alchemists and exploited the affinity between alchemy's belief in the transmutability of all material and his own aesthetic by adopting gold as a potent symbol of the ability of an element to cross the boundary between the material and immaterial worlds. Gold for Klein was the element and the color that best asserted this principle of a material transforming itself into something spiritual.
The highly ephemeral nature of gold leaf along with the intense resonance of its color is combined in Klein's Monogold panels to create works that evoke a strong sense of the spiritual significance of both the color and the material. In some panels the surface is essentially flat, creating a bold, deep monochrome. In others, Klein has fixed the gold leaf to the panel so loosely that the ephemeral lightness of the material is still visible and the surface constantly shimmers and fluctuates in the light. In MG 20 Klein has created an almost fluid surface that lies halfway between these two extremes with layers of gold leaf seeming to melt into a monochrome background in a way that suggests that the gold is transmuting from one state to another.