Conservation-restoration of Leonardo da Vinci's The Last Supper

Work on the conservation and restoration of Leonardo da Vinci's The Last Supper mural, much of it more harmful than helpful, has been carried out over many centuries, and continues.

Completed in the late 15th century by the Renaissance artist Leonardo da Vinci, the mural is located in the refectory of the Convent of Santa Maria delle Grazie, Milan, Italy.

[2] The scene is understood to depict the Bible verse John 13:22, showing the reactions of the Twelve Disciples at the Last Supper to Jesus's announcement that one among them will betray him.

[10] Leonardo used red chalk and black paint on top of the lead white to sketch out his image, before adding countless layers of mixed pigments.

The refectory of Santa Maria delle Grazie sits in a low-lying part of the city, prone to flooding and damp.

[13] In 1796, French forces, under the orders of Napoleon, took control of Milan and used the refectory of Santa Maria delle Grazie as their stables.

"[15] The Last Supper was almost completely lost on August 16, 1943, at the height of World War II in Italy,[16] when a Royal Air Force bomb struck Santa Maria delle Grazie, destroying the roof of the refectory and demolishing other nearby spaces.

[17] Giuseppe Mazza was hired by the priests of Santa Maria delle Grazie in 1770, to work on restoring and conserving The Last Supper.

[19] Mazza attempted to remove Michelangelo Bellotti's additions by using an iron scraping tool,[18] then filling in areas with an oil paint mixture and repainting the work as he chose.

[18] In 1821, Stefano Barezzi, convinced that The Last Supper was a conventional fresco, attempted to remove the work from the refectory wall.

[20] In 1924, the Italian painter Oreste Silvestri led the task of cleaning Leonardo's work, as well as applying new plaster to the edges of the painting.

[20] During these cleanings, Pelliccioli revealed many of Leonardo's original details, such as the Assisi embroidery design on the tablecloth and the gold lettering on Judas's robe.

[22] The restoration team removed the numerous layers of shellac, paint, and oils using "solvent applied with tiny blotters of Japanese paper.