The marble reliefs with the amazing effect of light and shade were originally decorated in gold leaf, ultramarine blue, red and brown with small parts in gold metal and fake precious stones. The portals with their delicate and fine inlay enchant for their care in the particular sculptural and for their poetry.
Before and after
POLYCHROME SCULPTURES OF THE CATHEDRAL OF MILAN
"ON THE TRACKS OF COLOR"
The key to interpreting a restoration intervention often focuses on the aesthetic result achieved, completely bypassing the process that led to the conservation of the artefacts. The portal of the northern sacristy was shrouded in a mystery, which had become increasingly difficult to solve over the centuries. How was it finished? Was it decorated? Did it still retain traces of the decorative apparatus? These questions, during our work, have found an answer and provided new insights to scholars. Sometimes the answers are complete and satisfying, at other times they are only partial, the result of intuitions that have arisen by observing a detail or a small fragment of color. The restorer's modus operandi is guided by historical, technical and cultural information, made available by scholars and officials responsible for the protection of the property.
THE WORK OF TWO GREAT MASTERS
The portal of the Aquilonare sacristy is the work of two master craftsmen who worked for the building of the cathedral since the origins of its foundation. Giacomo da Campione has been involved since 1387 in the building sites for the construction of the Cathedral, with the title of “magister a lapidibus vivis”. He was entrusted with the creation of the sculpture of the portal which began in 1389 and ended in 1395. Giovannino de Grassi has been working since 1389 in the construction sites of the Cathedral as an architect, sculptor and painter. He was entrusted with the pictorial decoration of the portals of both sacristies. Recent studies entrust the pictorial decoration with gold leaf, azurite and umber, also to Giovannino's brother, Parrino De Grassi, with whom he also created the figures of saints painted on the surface of the corner pillars.
Their work still characterizes the rear of the cathedral today. Both artists died in 1398, within a few months of each other, in mysterious circumstances, at the height of their careers. They left a fundamental heritage, a set of guidelines, including preparatory drawings and projects, which influenced and characterized the continuation of the construction of the cathedral in the years to come.
THE DELICACY OF POLYCHROME SCULPTURES, A RESTORATION IN
The restoration of polychrome sculptures is an extremely complex activity and simultaneously tackles different conservation problems, on supports of a non-ordinary nature such as oil painting applied to marble, or the gilding of sculpted surfaces. These are very delicate finishes, compromised by clumsy attempts at maintenance and by centuries of oblivion.
Certainly one of the most faced and important topics in the restoration is the cleaning phase. With this "fundamental" activity, the restorer tries to re-establish a balance between the visible nature of the work and its conservation, implementing a series of actions that aim at the rediscovery of the "colors and the original substrate" and at the conservation of the work in time. We are used to thinking that works, whether pictorial or sculptural, are simply "dirty" or damaged before a restoration. It is not so. The history of a work must absolutely contemplate the maintenance activities, the rethinking that occurred in the various eras, the attempts at "modernization" and other activities carried out to try to preserve it, update it, prolong its life or change its appearance. The sculptures of the Gothic portal, weighed down by more than 600 years of history, appeared to be covered with a complex layer of dust, mixed with the black smoke of the candles, layers of protective waxes of various kinds and drying oils mixed with pigments. These substances were superimposed on the pictorial finishes, on the very delicate drawings and spread into the interstices of the precious carvings of the sculptures. The restoration operations began by gently lightening incongruous deposits, working layer by layer and testing each step with caution and behind a continuous punctual check to check the result.
THE PORTAL DECORATION:
A "POLYCHROME MINIATURE"
These chromatic finishes, and the details that characterize them, are very reminiscent of the miniatures present on medieval manuscript codes characterized by bright colors and very fine gilding. One of the peculiarities of the portal decoration is represented by the figures of saints and martyrs "drawn" and painted on the small pillars in the central part. These figures were painted directly on the marble, marked by a dark border. The figure of St. George and the dragon is the only monochromatic one and has very material strokes of light made with lead white.
The close encounter with these surfaces, together with the analysis of scientific data, confirms the fact that the technique used was that of an oil paint on a stone support prepared with an oily white lead primer.