Short answers, pulled from the story.
Roman sculptors worked primarily in marble sourced from across the Mediterranean. They also used bronze, travertine, tufa, basalt, granite, and porphyry. Although most surviving Roman sculptures appear unpainted today, traces of pigment indicate that polychromy was widespread in antiquity.
By the 2nd century BCE, most sculptors working at Rome were Greek, many of them enslaved following military conquests such as the fall of Corinth in 146 BCE. Romans did not consider sculpting a true profession; at most it was accepted as a hobby, and the names of individual sculptors were very rarely recorded.
The Ara Pacis, or Altar of Peace, was dedicated in 13 BCE and has been called the most representative work of Augustan art. Its elaborate figural reliefs exemplify the official Greco-Roman style at its most classical and refined.
During the Republic, portraiture emphasized unsparing realism; depicting a man with his physical flaws intact was considered a mark of character. In the Imperial era, idealized statues of emperors became widespread, closely tied to the state religion, and portrait busts sent to provincial basilicas served as a primary tool of imperial propaganda.
After 476 CE, many sculptures were lost, destroyed, or stripped for reuse as spolia in new buildings throughout the Middle Ages. Interest revived during the Renaissance, when ancient sculpture became a formative influence on Western art in the 15th and 16th centuries.
Roman marble sarcophagi date mostly from the 2nd to the 4th century CE, reflecting a shift in burial customs from cremation to inhumation. They were produced mainly in Rome and Athens and exported across the empire; they were always expensive and reserved for the elite, with most examples being relatively plain and only a few featuring elaborate carved reliefs.