APPENDIX 2

The treatment tests carried out by Mauro Pelliccioli in the 1940s and 1950s.

The work which Pelliccioli began in the Arena Chapel in Padua during the Second World War and briefly continued some years later was not aimed at the restoration of the entire painting cycle, but was rather a series of treatment tests on some sample sections of the frescos. The results of these tests, however, provoked such criticism and suspicion as to bar the restorer from any future involvement in work on the chapel. 
In 1944, soon after the bombing attack that partially destroyed the nearby Eremitani church, with the accompanying loss of most of the frescos in the Ovetari chapel, the Superintendencies of Venice and the Municipality of Padua began to consider for the first time the possibility of removing the frescos from the Arena chapel and store them in a safe place. As a consequence, Mauro Pelliccioli was invited to Padua to perform some tests in order to verify the feasibility of such a treatment should it prove to be necessary and to identify the most suitable methods to employ. The restorer carried out his tests on the vault, removing four roundels and using both stacco and strappo techniques. The strappo method proved problematic right from the start due to the strong cohesion between the paint layer and the plaster of the frescos, and was thus employed on one roundel only. However, the stacco operation did not prove to be much less difficult, requiring the demolition of the underlying masonry and causing a considerable loss of the original plaster in the surrounding areas.
In 1952 Pelliccioli was again invited to Padua to perform a test “dusting” of the fourth vertical register on the left wall, which includes the panels of the Blossoming of the Stems, the Resurrection of Lazarus, and the Noli me tangere. The treatment was carried out on the recommendation of the 2nd Division of the Higher Council for Antiquities and the Fine Arts in the Ministry of Education, which had been called upon by the Superintendency for the Monuments of Venice in 1948 to issue an opinion concerning the removal of the thick, uniform dust deposits on the frescoed surface.This had always been a problem for the paintings in the chapel, but no doubt it had been aggravated during the war when various steps were taken both inside and outside the building to protect the paintings, employing considerable quantities of sand, either loose or in bags.
However, the results of the treatment on the frescos in the fourth register, which was still in progress in May 1952, failed to convince some members of the 2nd Division of the Higher Council. They felt that the cleaning had been “taken too far”, and it was suggested that Pelliccioli had been using caustic substances such as soda or organic chemicals which remained on the paintings and might in time lead to the deterioration of the frescoes. Professor Enrico Crepaz of the Institute of Industrial Chemistry at the University of Padua was given the task of determining whether such substances were present. Although his findings were negative, the question concerning the conservation of Giotto’s frescoes had now been raised. Given the responsibility, both at a national and an international level, that a restoration would involve, the 2nd Division of the Higher Council called for the setting up of an international panel of experts with the aim of examining the technical and scientific issues related to the restoration and conservation of the chapel and suggesting the best treatments to follow. This proposal was accepted by the Ministry of Education and the Istituto Centrale del Restauro was entrusted with the task of carrying out the preliminary tests on the condition of the frescoes, as these had not been performed prior to the cleaning of the three panels.
From 21 to 23 May the Commission met in Padua and once again examined the panels treated by Pelliccioli, carrying out a close-up examination of the condition of the frescoes and the extent of Pelliccioli’s cleaning, as well as asking the restorer directly about the techniques employed.
From the minutes of the meetings, we can infer reasonably accurately what materials and methods had been used.
Cleaning To remove dust deposits, mould and residues of protein based consolidants used in previous restorations, Pelliccioli used the following methods:
-	for the frescoed areas, slightly damp sponge-cloth compresses were applied several times, a technique previously employed in Assisi. The water used to dampen the compresses also contained formaldehyde as a disinfectant. The same method was also used, though more carefully, for the secco areas which did not contain azurite;
-	in the azurite secco areas, which had severe decohesion problems, the wet cloths were simply placed on the surface and then removed, thus cleaning solely by absorption. Another method was also used for these areas, though the minutes are not clear on what criteria was used to choose between the two techniques. This involved a dry method of cleaning: lightly rubbing the surface with a gummy paste made of wheat flour and copper sulphate, which did not leave any residues. Pelliccioli provided a brief description of how to prepare it and said he had been given the recipe by a German restorer in the 1930s.
Consolidation. To restore cohesion to the azurite secco sky and robes, as well as to the slightly lifted metal leaf, Pelliccioli used shellac diluted in ethyl alcohol. In the frescoed areas he applied gum arabic in order to brighten the colours and also as a mild consolidant. The gum was diluted in water until it left no reflective marks on the paint.
It is known that by the time Pelliccioli was asked to explain his methods the commission had already expressed a judgement, following its on-site inspection. Agreement had been reached that the treatment had been too drastic. The reasons given were as follows: the cleaning method using wet cloths, while effective on frescoes in good condition, when applied to the clearly decohesed paintings in the Arena chapel had caused the removal of a substantial part of the original paint layer. Further, together with the powdery paint, the treatment had also removed highly delicate glazes which Giotto had used in the faces and which were still plainly visible on the panels which had not been cleaned.
Pelliccioli’s work in Padua effectively came to an end with the report of the International Commission, which called on work to be suspended until more effective cleaning and consolidation methods could be devised and suitable measures could be taken to air-condition the Chapel and reduce the amount of dust present.