The most important characteristic of abstract art is that it has no recognizable subject. Other characteristics often include an "all over the canvas" approach and a high-energy kind of application process.
Abstract art can also be characterized by its frequent use of very large canvases. Often these canvases are situated in peculiar ways, such as laid on the floor, to achieve the desired outcome. Abstract artists also tend to treat all parts of their canvas, not just the center, as important. This is why nearly all parts of the canvas are covered in paint. Abstract art often uses unusual ways of applying paint, such as letting thinned paint drip, swashbuckling with paint brushes and even "writing" paint to the canvas.