It has been the subject of a detailed 1969 study by Colette Dufour Bozzo, who dated the outer frame to the late 14th century,[16] giving a terminus ante quem for the inner frame and the image itself. Bozzo found that the image was imprinted on a cloth that had been pasted onto a wooden board.[17][18]
The similarity of the image with the Veil of Veronica suggests a link between the two traditions.