Madonna and Child with a Kneeling Angel is a delicately sketched drawing in brown ink by Italian Renaissance painter Fra Bartolommeo della Porta. Examining it with the naked eye, one would have no clue that another sketch of a Madonna and Child existed on the back, because the drawing was adhered securely to another piece of paper. But when Anne Driesse, Conservator of Works of Art on Paper in the Straus Center for Conservation and Technical Studies, viewed the Fra Bartolommeo drawing under transmitted light and transmitted infrared (IR) light sources, the presence of a second drawing on the back—a preliminary sketch or later variant of the composition on the front—became quite clear.
Assisting Driesse in her investigation was the Foster + Freeman VSC5000 Video Spectral Comparator (VSC). VSCs are widely used in the forensic field—to examine counterfeit money, fake passports, and forged documents—and have proven to also be a great tool in the field of conservation to aid in the identification of watermarks, media, and underdrawings. With a click of a button, the VSC delivers images of an artwork under a variety of light sources—normal, ultraviolet (UV), IR, and transmitted (light that has passed through a material), for example.
Because the drawing was adhered to a secondary support paper, revealing this verso drawing was not simply a matter of flipping the paper over. After careful testing, Driesse slowly humidified the drawing for 1 1/2 hours using what’s called a wet blotter/Gore-tex package. Most of us know Gore-tex as the fabric used in waterproof clothing. It’s breathable and allows moisture vapor (sweat) to pass through the membrane. Conservators use a wet blotter positioned on top of Gore-tex so that the water vapor will pass through the Gore-tex and slowly humidify the object below. This is exactly how Anne was able to soften the adhesive on Fra Bartolommeo’s drawing, which then allowed her to remove the mount from the back. She then gently scraped away residual adhesive with a scalpel and spray-washed it to remove overall staining, a process she repeated multiple times over a few days.
Under the careful hands of Anne Driesse, Fra Bartolommeo’s hidden Madonna and Child was finally brought to light.