1. In an object-oriented computer system, a method for defining compositing operations in a graphics environment, said method comprising the steps of: creating a first object comprising a rendering method; creating a second object, said second object implementing a composite interface, said second object defining rules for a compositing operation, said second object comprising a method for creating an instance of a third object; setting said second object as a rendering attribute of said first object; creating said third object, said third object implementing a composite context interface, said third object comprising a method for compositing image elements, said third object maintaining state for said compositing operation; invoking said method for compositing when said rendering method is executed.