The stole is a scarf-like vestment worn at liturgical functions over the alb but under the dalmatic and/or chasuble. It is worn around the neck and equally down each side of the body by priests, and over the left shoulder and tied on the right side by deacons. It matches the liturgical color.
The stole was originally used as a scarf, and also to wrap the face in burial. According to some sources it was worn by Roman civil officials, including judges, as a sign of their office. By the 6th century, the stole was used throughout the Latin Rite. By the Council of Mainz in 813, all clerics were required to wear the stole at all times. Thirty years later Rome decided that it only needed to be worn while vested for the liturgy.