Like other American colonial colleges, Penn borrowed its 18th-century Commencement rituals directly from the English universities. In England the history of academic dress reaches back to the early days of the oldest schools. As early as the second half of the fourteenth century, the statutes of certain colleges prohibited "excess in apparel" and required the wearing of a long gown. It is still an open question as to whether academic dress finds its sources chiefly in ecclesiastical or in civilian dress. It is often suggested that gowns and hoods were the simplest, most effective method of staying warm in the unheated, stone buildings which housed medieval scholars.
In April 1887, on the recommendation of a committee of the faculty, the Trustees adopted the "'Pennsylvania' System of Academic Costume." The colors and trimmings of hoods and caps were regularized according to faculty and degree. Beginning with the Commencement of 1887 the "'Pennsylvania' System" was published in each year's program and adherence to its rules was expected of trustees, faculty and students alike. Beginning in 1896, the "'Pennsylvania' System" was superseded by the "Intercollegiate System," which has continued in effect to the present time.
The gowns used in American academic ceremonies vary according to the highest degree awarded to the wearer.
- The gown for the bachelor's degree has pointed sleeves. It is designed to be worn closed.
- The gown for the master's degree has an oblong sleeve. The rear part of its oblong shape is square cut and the front has an arc cut away. Master's gowns may be worn open or closed.
- The doctoral gown is a more elaborate costume faced down the front with black velvet and across the sleeves with three bars of the same; these facings and crossbars may be of velvet of the color distinctive to the field of study to which the degree pertains. The doctoral gown has bell-shaped sleeves and may be worn open or closed. Some institutions have authorized doctoral gowns in colors other than the customary black; holders of the University of Pennsylvania Ph.D. may wear red and blue gowns.
The mortarboard cap is standard, although soft square-topped caps are permissible. Recipients of doctorates may wear a gold tassel fastened to the middle point of the top of the cap; all others wear black. At Commencement, graduates wear the tassel on the right side, moving it to the left when their degree is conferred. Faculty participating in academic ceremonies wear the tassel to the left throughout the proceedings.
The hoods are lined in silk with the official color or colors of the institution which granted the highest degree held by the wearer; more than one color is shown by division of the field color in a variety of ways, such as by chevron or chevrons. University of Pennsylvania graduates wear a hood lined in red with a blue chevron. The binding or edging of the hood is in velvet, with widths of two inches, three inches and five inches for the bachelor's, master's and doctoral degrees respectively; the color of the border indicates the field of study to which the degree pertains. The colors signifying degrees granted by the University of Pennsylvania are as follows:
- Arts and Letters (B.A., M.A.), white
- Science (B.S., M.S.), golden yellow
- Business Administration, drab
- Nursing, apricot
- Medicine, green
- Law, purple
- Fine Arts (including Design), brown
- Dental Medicine, lilac
- Veterinary Medicine, gray
- Education, light blue
- Social Work, citron
- Philosophy (Ph.D.), dark blue