Summary
The paper deals with the use of digital visualization technologies to communicate the history of those works of art that have been dismembered or altered over the course of the centuries. In particular, the paper focuses on some medieval frescoes discovered behind the 16th-century altarpieces in the Florentine church of Santa Maria Novella. Detached in the 19th century, these frescoes have been located in different places, to the point that their original location was forgotten. Only recently they were relocated behind the altarpieces. Now the question arises how to properly communicate these vicissitudes to visitors.

Innovative VR tools and techniques
• The paper deals with both augmented reality (through mockups and markers) and videomapping or spatially augmented reality in order to show, through hand-held devices or projections, different layers of a painted wall (sinopias, detached frescoes, altarpieces).

VR in education
• AR is used to overlap objects on the screens of mobile devices, in order to make clear the changes in the church’s altars and walls over the course of the centuries
• Altarpieces are used as markers; the underlying frescoes, physically inaccessible without moving the altarpieces themselves, are made virtually accessible on the screen of mobile devices
• AR allows the simultaneous presentation of more layers, including the sinopias beneath the detached frescoes
• Videomapping is proposed as an alternative solution to project the detached frescoes on the walls and virtually integrate the surviving medieval decorative frames