Proto-Cubism color, simply by eliminating color from his paintings, Picasso in 1908 concentrated on form. Kahnweiler notes: "Derain, too, had abandoned decorative light painting in 1907", Kahnweiler writes, "preceding Braque by a few months. But from the outset, their roads were diverse. Derain's endeavor to retain fidelity to nature in his painting separates him forever from Cubism, no matter how closely his ideas may otherwise parallel those of Braque." And Derain was not the only one to venture along the path of Cézanne, only to turn away from it in the coming years. Chagall, Friesz, Matisse, Dufy, Redon, Vlaminck and Modigliani
Crystal Cubism towards the end of 1916, with an art world still under the pressures of war, to show the parallels between the poetic theories of Guillaume Apollinaire of Max Jacob and himself in marking the burgeoning of a new era for poetry and artistic reflection. In "Nord-Sud" Reverdy, with the help of Dermée and Georges Braque, exposed his literary theories, and outlined a coherent theoretical stance on the latest developments in Cubism. His treatise "On Cubism", published in the first issue of "Nord-Sud", did so perhaps most influentially. With his characteristic preference for offense rather than defense, Reverdy launched an attack