There is also a tradition of friends buying the newly appointed bishop his first zucchetto. A white zucchetto and a white bishop's mitre adorned John Paul II's head. The zucchetto is never worn with a suit. The most immediately noticeable feature is a white cassock and zucchetto (skull cap). Others allude to its shape as closely resembling a cardinal's skullcap or zucchetto. Similar to the yarmulke is the zucchetto worn by Roman Catholic clergy. The zucchetto and the biretta are scarlet, the distinctive color of cardinals' vesture. The pope customarily wears a white zucchetto to match his white cassock. In turn, the prelate is "privileged" to wear his zucchetto, not entitled. The zucchetto is always worn beneath the mitre or the biretta. The zucchetto is also not worn at any occasion where the Blessed Sacrament is exposed. In the Catholic tradition, the zucchetto is most commonly made of silk or polyester fabric.