After the Antique. The relief with riders facing left thought to be from the West frieze, the riders facing right thought to be from the South frieze of the Parthenon. Provenance: The Metropolitan Museum of Art. The collection and exhibition of plaster casts was considered an integral component of museums and educational institutions in the second half of the 19th century. Prominently displayed, they offered access to the full range of three-dimensional Western European art, from architecture to sculpture to the decorative arts. No stigma was attached to reproductions. Plaster casts were considered an excellent means of study, offering a convenient means of close-up analysis and a sense of original scale.