What is the Holy Face of San Silvestro?
This image, the Holy Face of San Silvestro, is kept in the Matilda chapel of the Vatican Palace in Rome. In the nineteenth century is was moved to the Vatican from church of San Silvestro in Capite. The earliest known records for it date to 1517, when records show that it exhibitions were prohibited to prevent competition with the Veronica.
It is clearly a painting on a piece of wood.
Like the Genoa image, it is very similar to one of the many claimants to the title of the Veronica Veil and as such it fits that claim as well.