F is based on the interior of one type of train on the New York MTA. The F Line is one of the lines these cars run on. The F train is the subway that was closest to my home in Brooklyn at the time, so I spent a lot of time looking at the insides of these cars. The central shape is the door of the car. It is flanked by two benches (see my painting, Bench) and two brown panels which often hold advertisements or subway maps.