Abstract art can be a painting or sculpture (including assemblage) that does not depict a person, place or thing in the natural world. Note that works of art that represent the world in exaggerated or distorted ways (such as the Cubist paintings of Paul Paul Cézanne and Pablo Picasso) are not abstract, for they present a type of conceptual realism. With abstract art, the subject of the work is based on what you see: color, shapes, brushstrokes, size, scale and, in some cases, the process (see action painting).