Three months ago, the volunteer preservationists of Florence set out on a Herculean task—de-graffitiing Giotto’s Campanile, the tricolored bell tower of the Opera di Santa Maria del Fiore. As they scraped and scrubbed, an even larger task emerged: how to convince people to stop signing the building in the first place.

So they built an app. “Autography” allows would-be scrawlers to make their mark in a less obtrusive way, via special digital tablets installed around the building.

Sample "graffiti" made with the Autography app. (Photo: Autography)

Sample “graffiti” made with the Autography app. (Photo: Autography)

Visitors can “choose the surface (marble or wood, for example), the color, and the instrument they want to use (felt pen, paintbrush, aerosol),” architect and head volunteer restorer Beatrice Agostini told Agence France-Presse. They doodle with their fingers, and save their masterpieces to an online gallery.

At the end of the year, the digital artworks will be printed out and filed away in the archives—far more permanence than regular graffiti manages. “The idea was to raise awareness among visitors about vandalism,” wrote the Opera in a statement, “but also give them the chance to leave behind a record, an everlasting sign of their passing through.”

Every day, we track down a fleeting wonder—something amazing that’s only happening right now. Have a tip for us? Tell us about it! Send your temporary miracles to [email protected].