Why did Henri Matisse use gouache-painted paper for his late cutouts?

Henri Matisse used gouache-painted paper for his late cutouts primarily because he found the process of arranging these cut-out sections far more manageable than working directly with paint on canvas.1

As his health declined in his later years—particularly after a 1941 surgery left him frequently bedridden—this technique allowed him to continue creating despite his physical limitations. Matisse referred to this innovative method as "drawing with scissors" or "drawing in paper". By hand-painting sheets of paper with gouache beforehand, he was able to achieve the exact hues he desired, which he then cut and pasted to define figures through the spaces between the shapes. This approach served as the culmination of his lifelong search for a perfect synthesis of color and form, resulting in works that were among the most daring and optimistic of his career.213