http://www.kunsthaus.ch/en/the-collection/conservation/examples-from-the-world-of-art-conservation/final-report-april-2013-september-2014/?redirect_url=title%3DMasticage

Kunsthaus Zürich

Final report 
April 2013 – September 2014

Structuring technological facts, formulation of treatment guidelines and implementation of conservation and restoration measures

The last year and a half of the project were labour-intensive and exceptionally interesting. For example, our team and additional external experts held another meeting in the early summer of 2013. Unlike the previous large international colloquium of 2013, which also saw the participation of art historians in order to discuss the aesthetic aspects of the restoration project, this meeting exclusively addressed conservation issues. This refers to interventions and materials that are meant to preserve an object's material integrity as well as to prevent future damage.

To be able to start with the second part of the project – the conservation and restoration measures – the answers to a number of questions pertaining to art historical and technological issues were still needed. As a consequence our team undertook a second trip to Paris together with Dr. Philippe Büttner, to resolve those questions that were left unanswered with the help of colleagues from the Fondation Alberto et Annette Giacometti (FAAG). Intensive rounds of discussion, the backdrop of vast archives and sculptures owned by the FAAG and the help of long-time director Véronique Wiesinger and a conservator helped us to develop answers to our queries. Not only did we gain insight into the conservation treatment methodology of the FAAG, but the comparison with their Giacometti sculptures on site also enabled us to gather a deeper understanding of our own Giacometti collection. By the same token we were able to selectively integrate important information from the FAAG's documentation.

Unfortunately, the completion of our trip also coincided with the end of our collaboration with a member of our team, Patrick Decker. This was due to the fact that the collective labour agreement that was in force only allows a maximum duration of three years for project-based positions. Patrick assisted our project greatly and, with his passionate engagement and his highly specific knowledge of bronzes and casting techniques, has enduringly left his mark.
For the last year of the project, Kathrin Harsch has now joined our team.

During the 2013 colloquium the plaster works were categorised according to their appearance, which was caused by their previous usage (A: visually not significantly altered, B: visually altered and C: visually and structurally highly altered artwork). This categorisation and the resulting implications gave us a conceptual basis early on to define both the condition of each individual plaster work as well as the ensuing consequences for its restoration. The methodology and technical possibilities, however, first needed to be determined by performing extensive practical tests. To that end we initiated a series of comprehensive bonding, consolidation, filling and plaster retouching tests.
Throughout the tests, materials were used that are age-resistant and non-toxic, and do not yellow or become brittle. Depending on the type of measure undertaken they also of course had to meet other demands, for instance retouchings needed to be reversible, opaque or matte.

In addition there was a small number of objects that suffered from substantial losses. In these cases, we embarked upon tests with a 3-D scanner in collaboration with EMPA (Swiss Federal Laboratories for Material Sciences). Using the existing intact bronze sculpture (which was made from the plaster template) as a scanning model, the intention is to gather data that can provide the basis for a 3-D print. This should make it possible to faithfully reconstruct the original surface of the plaster and close the losses accordingly. However, this calls for an absolutely precise point-by-point exploration of the surface of both objects with a laser. The data then need to be processed for compatibility, to thus make the exact filling of the loss possible. It was initially hard to gage how much computing power and mathematical algorithms would be required. Thanks to the Giacometti Project, a crucial impulse was given to venture into in this entirely new field. To perfect this method and bring it to a point where it can be put into full practical use, however, will probably require another project all on its own.

After completing the 3-D scanning and material tests, we somewhat belatedly started on the practical restoration. The technical examination, research and tests had taken more time than expected. Both the preparations for the highly acclaimed exhibition of the technological results in 2012 and the international colloquium turned out to be considerably more extensive and exacting than initially imagined.
All objects were surface cleaned and conservation treatment was executed when required, i.e. plasters were stabilised or consolidated. Smaller losses were filled and retouched. As a result, each sculpture could be perceived as a unified object again. We did not carry out major invasive interventions meant to restore the work to a putative original state. For example, removing all traces of yellowed layers of shellac, which is in fact an unmistakable sign of the plaster’s use as a casting template. We, i.e. the conservation department, are convinced that the evolved condition of the work as well as the recognisability as a casting template are important elements of an artwork’s history; therefore, they need to be respected.

Our collaboration with Roy Oppenheim should also be mentioned. He visited us regularly in the past four years and has recorded the project’s progress on film. When he is done with his work, a film document will be available that shows the long road and the many steps the project has travelled to reach its completion.

We’ve come a long way! In 2010, as we started to study Giacometti, his plaster works, the casting techniques and the condition of the objects, we were confronted with the challenge of interpreting an almost infinite number of traces and puzzling surface phenomena. With the help of many colleagues who have supported us and through our deep engagement with Giacometti’s plaster works, we became more and more confident in our interpretation of techniques and damage. Today, we – the conservators of the Kunsthaus Zurich – are proud to be seen as part of a small group of Giacometti experts when it comes to technological research and conservation studio practice. We were able to find an integral conservation and restoration concept that we have applied successfully.
We are looking forward to showing a selection of our newly restored artworks, as a conclusion to our project, in early 2015. They will be exhibited within a presentation of the collection of the Kunsthaus and the Foundation.
Thanks to our generous sponsors we were given the possibility to dedicate ourselves fully to the project with all its enthralling tasks and enriching findings.
We are very grateful for this unique opportunity.
The Giacometti Project Team 2014

Meeting to address conservation issues
Meeting to address conservation issues
Rolf Fritschi explains a possible bonding strategy
Rolf Fritschi explains a possible bonding strategy
Patrick Decker talking to Hubert Lacroix (Fonderie Susse)
Patrick Decker talking to Hubert Lacroix (Fonderie Susse)
Kathrin Harsch
Kathrin Harsch
Testing of retouching materials on plaster
Testing of retouching materials on plaster
Kerstin Mürer working on a filling
Kerstin Mürer working on a filling
Tobias Haupt doing a retouching
Tobias Haupt doing a retouching
Roy Oppenheim (arttv)
Roy Oppenheim (arttv)