Müller has specialized in documenting the process of painting subways, which is considered the top prize within the international graffiti world. Subways hold such a high value because of the difficulty, the danger and risk involved. Subway painting has separated itself from the common graffiti community as it is a more secretive sect of the elite who push the bar and have created something which can be likened to an extreme graffiti sport. Regardless of the subway system or the country, razor wired fences have to be cut or climbed, motion sensors, cameras, and alarm systems have to be overcome and if something goes wrong, be ready to run.
Poor Bob !