Persons who have earned a doctoral degree or who have been granted an honorary degree are entitled to wear academic doctoral gowns. The gowns are usually black, but some institutions, such as Harvard and Wesleyan, use an alternate robe in the color of the institution. Robes in the discipline color (such as light blue for education) are also common. Some universities, such as Princeton, also offer robes trimmed with the insignia of the institution or banded with the institutional color. All robes have bell-shaped sleeves with three velvet bars and velvet panels at the front opening. Gowns are worn open or closed, depending upon the style. The more common style is closed. Doctoral robes are always worn with a hood indicating the discipline in which the degree was received and the institution that awarded it. Doctoral gowns are worn with either the traditional mortarboard cap, with a gold tassel, or a soft cap with a gold tassel. The tassel is worn on the left.