One of the first tools that Alberto Felici, a restorer at the Superintendency of Archaeology and Fine Arts of Florence, used to assess the frescos in the Brancacci Chapel was his hands. Working methodically, Felici tapped the painted surface, letting small vibrations and muffled sounds hint at damage beneath the art.
This work guided Felici on how layers of the fresco—from the painted surface to the plaster to the arriccio, or second coat of plaster—were adhering to or detaching from the wall. It is a good first assessment that indicates weak areas, he says. Care was needed, given that a small fragment painted by Filippino Lippi in the late 15th century had previously become detached—a signal that this inspection was necessary.
“But there is an issue at this point,” Felici says. A restorer must be able to understand if damage “is ongoing, if it is something that happened one year, one week, or the day before. This is impossible with this assessment,” he says.
This tap test, with its hands-on interaction with the art and intrusive scaffolding to access works in the vaulted ceilings, is a manual and highly subjective process. Experts like Cristiano Riminesi, a researcher at the National Research Council’s Institute of Heritage Science, agree it could be improved by more data.
“Although detachments are often recognised by the tap test, this method is time-consuming for larger areas, and its accuracy of execution and interpretation is too discretionary and subject to the individual skills and experience of the restorers,” he says.
