Painting is the practice of applying paint, pigment, color or other medium to a surface (support base). The medium is commonly applied to the base with a brush, but other implements, such as knives, sponges, and airbrushes, can be used. In art, the term painting describes both the act and the result of the action. The support for paintings includes such surfaces as walls, paper, canvas, wood, glass, lacquer, clay, leaf, copper and concrete, and the painting may incorporate multiple other materials including sand, clay, paper, plaster, gold leaf, as well as objects. The term painting is also used outside of art as a common trade among craftsmen and builders. Painting is a mode of creative expression, and the forms are numerous. Drawing, gesture (as in gestural painting), composition, narration (as in narrative art), or abstraction (as in abstract art), among other aesthetic modes, may serve to manifest the expressive and conceptual intention of the practitioner. Paintings can be naturalistic and representational (as in a still life or landscape painting), photographic, abstract, narrative, symbolistic (as in Symbolist art), emotive (as in Expressionism), or political in nature (as in Artivism).