Paul is a painter. Most of his works are abstract expressionist in style.
google image search
http://images.google.com/images?hl=en&source=hp&q=paul%20mccartney%20painti ngs&um=1&ie=UTF-8&sa=N&tab=wi
google web search
http://www.google.com/#hl=en&source=hp&q=paul+mccartney+paintings&aq=f&a qi=g1g-sx1&oq=&fp=2392fc58ef7a3a
cover of his art book published in 2000

" I don't think there is any great heroic act in going in slavishly every day and saying, "I must do this." So what I find is that I do it when I am inspired. And that's how I can combine it with music. Some days the inspiration is a musical one and other days it has just got to be painting."
— Paul McCartney