PRINCETON, NJ.- How ritual additions to the surfaces of African sculptures alter an object’s appearance and power over time is the focus of a fascinating new exhibition at the Princeton University Art Museum. These surface accumulations—such as layers of organic materials that have cultural and spiritual value, or encrustations that reveal the additions made by multiple hands—offer insight into the history and life of the object.

Surfaces Seen and Unseen: African Art at Princeton presents some 20 exceptional works of African art from the Princeton University Art Museum, including newly acquired works from the Holly and David Ross Collection as well as gifts and loans from important private collections.

“Collecting and exhibiting African art has been a priority of this museum in recent years,” said Nancy A. Nasher–David J. Haemisegger, Class of 1976, Director James Steward. “We are fortunate indeed to have the support of such good friends as Holly and David Ross in supporting these efforts.” He continued, “This exhibition affords an opportunity to highlight recent collections growth and to focus on an often undervalued aspect of African art in the rich physical layers that reveal both spiritual and ritual meaning.”

The exhibition, which is curated by Juliana Ochs Dweck, the Princeton University Art Museum Mellon Curator of Academic Engagement, is on view July 2 through Oct. 9, 2016 at the Princeton University Art Museum.

The original form of an African object sculpted by an artist may be added to over many years by a range of users. In some cases, substances such as soil, oils or grains applied to a sculpture during ritual offerings activated the object for power or healing and transformed the object’s patina. Other objects were empowered over time as ritual experts attached materials such as feathers, fabrics and mirrors. Masks were often repainted for subsequent performances.

Among the Kongo of West Central Africa, for example, a ritual expert attached medicines to a wooden figure, carved by a sculptor, to empower it as a container for spirits. An Urhobo mask, danced in southern Nigeria for the local water spirit, was recolored by its owner for new performances but also worn down through use. In northern Nigeria, a Wurkun specialist refreshed sculpted figures with libations of millet beer and seed oil so they could aid healing.

For much of the 20th century, dealers of African art in the West removed these surface accumulations, cleaning and polishing the objects to make them more desirable to collectors. More recently these additions, layers of color, encrustations and attachments have been studied and understood as significant artistic and cultural interventions.

Among the works on view will be a striking Dan mask (20th century), which incorporates wood, metal, encrustation and hair residue; a Senufo oracle figure (20th century) used as a divination device, whose underlying carved wooden body has been covered with cloth, mud, twigs and feathers and a Kongo Nkisi figure (early 20th century), which would have been carved by an artist and then passed to a ritual expert, who embedded unseen medicines inside the object and affixed beads and fabric to augment its form and increase its power.