[3][4] In 1906, after he sold all his possessions,[5] he moved to Paris and became friends with the poets Guillaume Apollinaire, Max Jacob, and artists Henri Matisse, Georges Braque, Fernand Léger and Jean Metzinger.

Gris began to paint seriously in 1911 (when he gave up working as a satirical cartoonist), developing at this time a personal Cubist style.

[9] In A Life of Picasso, John Richardson writes that Jean Metzinger's 1911 work, Le goûter (Tea Time), persuaded Juan Gris of the importance of mathematics in painting.

[10] Gris exhibited for the first time at the 1912 Salon des Indépendants (a painting entitled Hommage à Pablo Picasso).

Unlike Picasso and Braque, whose Cubist works were practically monochromatic, Gris painted with bright harmonious colors in daring, novel combinations in the manner of his friend Matisse.

[18][19] Gris's works from late 1916 through 1917 exhibit a greater simplification of geometric structure, a blurring of the distinction between objects and setting, between subject matter and background.

The oblique overlapping planar constructions, tending away from equilibrium, can best be seen in Woman with Mandolin, after Corot (September 1916) and in its epilogue, Portrait of Josette Gris (October 1916; Museo Reina Sofia).

[20] The clear-cut underlying geometric framework of these works seemingly controls the finer elements of the compositions; the constituent components, including the small planes of the faces, become part of the unified whole.

[20] The geometric structure of Juan Gris's Crystal period is already palpable in Still Life before an Open Window, Place Ravignan (June 1915; Philadelphia Museum of Art).