THE CONCLUSION OF THE RESTORATION OF THE CAMPOSANTO MONUMENTALE IN PISA
The cathedral of Pisa is served by three ancillary structures: a baptistry, a campanile (the infamous torre pendente), and a monumental covered cemetery, the Camposanto. Begun in 1277, the Camposanto's peristyle walkway is lit by huge windows elborated with lacey, white marble tracery--marvels of the distinctive Pisan Gothic.
The vast expanses of interior wall were painted by a succession of Tuscan artists. The earliest, by Francesco Traini, date to 1336/41. Buonamico Buffalmacco, Stefano da Firenze, Andrea Bonaiuti, Antonio Veneziano, Spinello Aretino, Taddeo Gaddi and Piero di Puccio, continued the work into the 1390s. The sombre-to-dark subject matter of these over life-sized images--ascetic hermit monks resisting demonic temptation, a Last Judgment with the least compassionate figure of Christ in medieval Italian art, and a moralizing epic called the Triumph of Death--reflects the climate of fear and intense penitential religiosity that characterized the decades following the Black Death, which killed off one third of Europe in 1348/49.
On 27 July 1944, an allied grenade ignited the lead and timber roof of the Camposanto, which burned for three days, then collapsed. Of the 2500 sq meters of fresco, already in perilous condition, 600 sq feet were destroyed by falling debris or calcified by the heat. The remaining works remained in situ until the end of the war.
Buon fresco is painted into the wet plaster of the wall. Pigments and plaster then dry and harden together creating an image that is part of the wall, not a film attached to the wall. Despite the seeming inseparability of picture and wall, frescoes can be removed from the wall. Affreschi staccati or strappati consist of the layer of plaster, which is peeled off the wall using straps glued to images. The thin layer of painted plaster is then transferred to a canvas or wooden support. (As was the case at Pisa, the removal of the plaster exposed the sinopie, or underdrawings hastily sketched on to the wall to guide the artists.) The hair-raising process of detaching fresco, which can easily compromise the integrity of the work, has made it possible to rescue or remove mural paintings from architectural settings to preserve, display, or in the case of damaged works, restore them in a laboratory setting.
The surviving Pisan murals were deposed 70 years ago and were subsequently transferred from one support to another as conservation practices changed. The adhesivity of the casein glue initially used to fix the paint layer to wood, failed after mold penetrated the panel, requiring the ungluing and re-affixing of everything. To prevent intramural condensation from seeping into the panels, an elaborate system of sensors woven into a synthetic fabric was placed between wall and panel. These sensors adjust the temperature of the wall to within 3 degrees of the ambient temperature every 10 minutes, thus preventing condensation.
Thanks to three generations of restorers, the works as we see them today are more clear and legible than that than they were in the early 1940s. Apart from consolidating the surface and filling in lacunae, they also removed centuries of accreted dust and dirt. Given what they had to work with, the most impressive result has been the restoration of a fair amount of color, although the original hues are unrecoverable (the palette of the post 1348 works probably resembled the sugary colors and acid tones seen in the contemporary Spanish Chapel frescoes at Santa Maria Novella in Florence).
Affreschi staccati cannot be reaffixed to the wall, but the huge panels on which they were mounted were reinstalled in their original position, beginning in 2005 and ending in 2018.
