The architects devised a decorative scheme which had certain features in common for each station but gave each station a distinctive identity. The identity of each station was created through the use of color, symbolic plaques, and name tablets. Fine materials such as faience, terra-cotta, glass and mosaic tile, marble and Roman brick highlight the artistic qualities of the stations. The City Hall station employs distinctive Guastavino vaults which enhance the curved loop of the station. The IRT subway stations were a significant contribution to the creation of a public art.