"When I returned home to my room in the evenings I did monochrome gouaches on pieces of white cardboard and also increasingly used a lot of pastels. I was very fond of pastel tones! It seemed to me that, in pastel, each grain of pigment remained free and individual without being killed by the fixative medium, and I made some very large works, but, alas, when sprayed with a fixative, they lost all their brilliance and its tone darkened, and without fixative they unfailingly deteriorated and, little by little, turned to dust; the beauty of the color remained, but without pictorial strength.
I had no affection for oil paint. The colors seemed dead to me. What pleased me above all were pure pigments in powder form, such as I often saw at the wholesale paint suppliers. They had a brilliance and an extraordinary, autonomous life of their own. This was truly color in itself. The living and tangible matter of color.
What saddened me was to see that this incandescent powder, once mixed with glue or whatever medium intended as a fixative, lost all its value, became tarnished, its tone darkened. One might obtain the effects of impasto, but after it dried, it was no longer the same; the effective magic of color had vanished.
Each grain of powder appeared to have been individually killed by the glue or whatever fixative used to binding them together, as well as to the support.
Irresistibly attracted by this new monochrome manner, I decided to undertake the technical research required to find a medium capable of affixing pure pigment without altering it. The color value would then be represented in a pictorial manner. The possibility of leaving the grains of pigment entirely free, such as they are in powder form, mixed perhaps yet still independent in their semblance, seemed sufficiently auspicious to me. Art is total freedom; it is life; when there is imprisonment in whatever manner, liberty is restrained and life is diminished in relation to the degree of imprisonment."
Yves Klein, excerpt from « The Monochrome Adventure: the monochrome epic », 1960 ca., Overcoming the problematics of Art -The writings of Yves Klein, Spring Publications, 2007