The painting is signed ”L da Vinci” with the underlined letters ”Pinxt” directly below. Pinxt is an abbreviation of the Latin word Pinxit. Pinxit (from Latin: ”one painted”) is a stylized amendment added to the signature depiction of the name of the person responsible for a work of art, found conventionally in the late middle ages and the renaissance. It is known that Leonardo signed some sketches with ”I des,” which suggests ”Io designato,” that is, ”I drew this.”1

The signature was discovered in 1994 using very strong light. It is not visible in normal light. In strong light only the last i in Vinci is visible. In 2019 we started an in-depth analysis of the signature.

Raman spectroscopy performed on the signature found only one pigment, carbon.

Paintings conservator Ann-Marie Mild, SVK (Studio Västsvensk Konservering), Gothenburg, who made the UV/IR report, states: ”the area where the signature is located is untouched” and ”nothing speaks against that the signature has been there from the beginning”, see report below.

Paintings conservator Nina Olivier, Stockholm, who examined the signature area for the signature report states: ”the signature looks as if it has been partially removed in a previous conservation treatment”, see report below.

We have found no technical indications that the signature is spurious. The photo of the signature was taken using very strong light. Hue, saturation, brightness and contrast have been modified to enhance the letters. Microscopy, see photomicrograph below.

1Raymond Stites. The Sublimations of Leonardo da Vinci. Smithsonian Institution Press, 1970, 10.

Raman spectroscopy, signature pigment, carbon.

Signature pigment sample.

Roman emperor Domitian, Leonardo da Vinci, Titian, Tizian, Tiziano Vecellio, Roman emperors, Eleven Caesars, Undici Cesari, Domitianus, Isabella d’Este, Federico II Gonzaga, Mantova, Mantua, Italy, Francis I, Amboise France, Charles I England.