Visual texture is the illusion of having physical texture. Every material and every support surface has its own visual texture and needs to be taken into consideration before creating a composition. As such, materials such as canvas and watercolour paper are considerably rougher than, for example, photo-quality computer paper and may not be best suited to creating a flat, smooth texture. Photography, drawings and paintings use visual texture both to portray their subject matter realistically and with interpretation. Texture in these media are generally created by the repetition of shape and line.