One of Valletta’s finest architectural gems has been restored to its former glory, 13 years after plaster and pieces of stone fell from the main dome.

Located adjacent to Auberge d’Italie, Santa Caterina d’Italia was where Italian Baroque artist Mattia Preti learnt the rare technique of painting directly on the wall.

Although it was thought Preti invented this technique, research shows it was already being used in Malta when he set foot on the island in 1659. Preti perfected the technique, which two years later adorned St John’s Co-Cathedral.

The church, closed “for business for 13 years” according to parish priest Gino Gauci, opened again on November 25, feast of St Catherine of Alexandria, with a Thanksgiving Mass concelebrated by Cardinal Francesco Monterisi and Archbishop Paul Cremona.

The restoration process was very challenging because the masterpieces had been painted directly on the stone, and most of them were badly damaged. Restoration of the wall decorations in the large dome, depicting the life of St Catherine, took two years.

A reversible method was used throughout the restoration process, unlike the retouching system used in the 1960s which hid the original pieces in places.

Restorer Giuseppe Mantella insists he was a restorer, not an artist. “I cannot invent anything. I apply a scientific technique that reincarnates the masterpiece’s splendour without adding anything,” he said.

Born in Calabria, just like the renowned artist, Mr Mantella said restoring Preti’s work was a dream come true.

But this only marks the beginning of a larger project, commemorating the 400th year anniversary from the birth of the painter.

“In 2013 we plan to recount Preti’s story through his work in Malta – found in Saint Catherine’s church, Sarria church in Floriana, St John’s co-Cathedral and Mdina among others. We want Europe to come to Malta in 2013 to see Preti’s masterpieces. This is not just the island of Caravaggio. Preti has left a significant impact on architecture and artistic techniques used in Malta,” Mr Mantella said.

The painting of St Sebastian, found in Sarria church, will be restored at Malta International Airport, and the public will be able to observe the process.