Background artists take the storyboard and layout and produce final backgrounds. Final Backgrounds are fully colored and detailed, and they are the final images that appear in a project.
The Background artist can work in traditional pens/paper and/or paint or the new digital media world. Regardless of tools they should be able to consider light and shadow, create space using all the tricks of perspective, and create a variety of texture. They should be capable of very detailed work and still keep the overall purpose of the background in mind.
Perhaps most importantly they should be able to create space for and direct attention to the action. Good backgrounds do not attract too much attention to them selves. A perfectly done background will provide a rich experience to the viewer. Most viewers will remember the characters fondly, not realizing how much the background did to make them memorable.