After research was completed, conservators and curators worked together to come up with a plan of action. They decided to restore the statue of Septimius Severus to its 17th-century appearance in order to celebrate that period’s unique combination of creativity and science.
First and foremost, the sculpture needed to be structurally stabilized. Though some of the older fills and repairs had deteriorated, conservators tried to keep the historically significant restoration material in place whenever possible. Joints and fills were reinforced with modern material, which is more durable yet easy to differentiate from the original under close examination. Second, the sculpture was heavily soiled and needed extensive cleaning.
In order to retain evidence of the 17th-century restoration, new materials were added by methods that allowed them to be removed or undone in the future. Old fills and adhesive material were preserved by applying a viscous solution of acrylic resin to form a barrier between the old and new materials. The more recent damage to the marble (from the early 20th century) was isolated in a similar manner, so that the 21st-century additions can be recognized as separate and removed, if necessary, by future conservators. The cracks in the marble were filled with a modified plaster and toned with dry pigments to match the color and texture of the marble. Calcium carbonate, also known as whiting (essentially powdered chalk), was added to decrease the cohesive strength of the plaster, and ultrafine fumed silica was used to enhance its modeling and handling characteristics. These newer fill materials were shaped and modeled by hand with a variety of spatulas and sculpture tools.
Once the losses were filled and toned, Septimius Severus was returned to its rightful place in the museum’s new galleries as a work that honors both its classical origins and the rediscovery of antiquity in the early modern period.