Since 1953 the artistic production of Antoni Tàpies has definitely turned direction focusing on the problematic of matter. Consequently we are witnessing the reduction of the chromatic alphabet to a few colors, to the advantage of the material consistency of the pigs works that begin to take on the appearance of crumbly and peeling walls, bearing the imprint of the slow but relentless work of time, to which it accompanies a code of light signs, antithetical to the rough tactile exuberance of the material. As usual in those years, Painting no XLV proposes in the consequent title the author's intention to free himself from any descriptive temptation, while in other works the title of the work is simply given by the materials used. Content more than framed by the frame, which in addition to taking up the black recalls the idea of an older and aged object of which only the golden decorations at the corners remain, the painting lives on the ambiguous fusion of the dark background created with Spanish painting, starting from the backgrounds of the seventeenth-century still lifes, passing through the black paintings of goya, up to the dramatic Picassian evocations of the war. To tear the gloomy veil of the composition is the emergence in the lower part of the canvas of the rough sandy concretion: the revenge of materiality with its immanence on the transcendence of color.