Anyone interested in conservation will be astonished to see that the thirty-one wooden Renaissance architects’ models (including that of 1539 for St Peter’s by Antonio da Sangallo the younger) are currently exhibited at Palazzo Grassi without the protection of specific, individual controlled environment systems. For the exhibition “Renaissance: from Brunelleschi to Michelangelo”, Piero di Cosimo’s painting of the construction of a city flown in from Florida, the world-famous “Città Ideale”, from Urbino, and the San Bernardino panels from the Pinacoteca di Perugia are displayed without air-conditioned glass cases.
Clearly, the organisers have followed a different procedure from usual: maintaining the required atmospheric conditions throughout the building, in particular a humidity level of 55% (humidity, not temperature, is the vital factor). Since hygro-thermographs were not in evidence, I assume that sensors in the individual rooms must feed measurements to a central control panel. Given these conditions, the museum curators, the relevant committee, and the Ministry, must have been satisfied, and waived the requirement that exhibits be displayed in individual air-conditioned environments, as is normally the case.
Personally, I would be very pleased if the generalised use of the so-called “climabox” were abandoned. I do not like the uncritical acceptance of these devices, which are religiously invoked every time a work of art needs to be transferred to another location: “Don’t worry, we’ll use a climabox...”. The problems inherent in moving panel paintings need no rehearsing; an air-conditioned case seems to meet every objection. But there is a basic error in this approach, or at least a misunderstanding. The purpose of controlling the environment in which a work of art is displayed (for instance, with silicon gel in granular or sheet form) is not to create theoretically ideal climatic conditions, but to maintain for the duration of the exhibition the specific, individual conditions in which the work is normally kept. In most cases, such conditions are far from the theoretical ideal. A work of art tends gradually to adapt, often with some difficulty, to its home environment. Transposing it to another environment, albeit a theoretically ideal one, causes just that sudden change which inevitably produces short, medium or long-term damage. A climabox must therefore create the conditions in which the work is normally kept.
Although I very much appreciate the efficiency of the Palazzo Grassi organisers in achieving the best possible environmental conditions, I do not think they have found the ideal solution. For instance, a climabox protects a work from sudden environmental changes, and these are always likely to occur: what is there to prevent a large number of visitors from entering at the same time, possibly on a rainy day, all wearing wet raincoats? How quickly could the system react to restore optimum conditions?
Having said this, two other factors demonstrate the care taken to ensure the proper conservation of the works involved. First, optical fibres have been used for the lighting (with their high power of illumination and low lux quotient, these are highly efficient). Second, to prevent light-sensitive paper materials being exposed for too long a period, the exhibition is being interrupted for a month to allow for a change of drawings, and this at the height of Venice’s tourist season (mid-July to mid-August).
Finally, it is a pity that the catalogue makes no mention at all of the huge restoration project which lies at the origins of this exhibition. A book is needed to document that restoration of the grandiose model by Sangallo for St Peter’s, which was conducted with admirable organisation (essential in the case of a model made up of thousands of pieces and measuring eight by five metres) by Claudio Tinunin and Michele Benvenuti of Laboratorio Tlt.
Originally appeared in The Art Newspaper as 'A marriage of science and spectacle'