Conserving Canvas

Report on the experience gained at the Workshop: Water-based adhesives in canvas paintings’ structural conservation 

Palazzo Barberini – Conserving Canvas 2022 

The Gallerie Nazionali di Arte Antica, located in Rome and one of Italy’s leading cultural institutions when it comes to fine arts, initiated a project on structural treatments of canvas paintings. This project is part of the Conserving Canvas grant initiative by The Getty Foundation, an initiative that aims at knowledge exchange between different generations of conservation professionals on an international level, spotlighting the structural treatments for paintings on canvas. 

The GallerieNazionali’s project focuses on the structural problems of the three large paintings, namely Marriage of Peleus and Thetis, Bacchus and Ariadneand the Battle of Constantine and Maxentius.In a series of three workshops, each one addressing a different painting fromthe Throne Room of Palazzo Barberini, selected participants collaborated with the hosting team from Conservazione Beni Culturali(C.B.C.) on the research and treatment.  

SRAL paintings conservator Joanna Strombek was selected to join the first workshop in July this year. Together with her fellow conservation colleagues, Joanna focused on the treatment of Bacchus and AriadnebyGiuseppe Belloni, painted between 1665 and 1673. 

While all participants were experienced in carrying out structural treatments on canvas paintings, this case study offered the unique opportunity to practice this conservation method on a large-scale painting of 3,15m hight and 7,25m width. Not only the size of the canvas made this case study interesting. In fact, its deformations caused by its weight and the detachment of the glue paste lining, made this project highly intriguing.  

Natural Adhesives 

The decision was made to re-line the painting, using a water-based adhesive. This would reduce the impact in terms of toxicity and ensure a better reversibility.  
Before carrying out the treatment, the participants were introduced to these water-based adhesives and gels. Under the guidance of the C.B.C. senior conservator Matteo Rossi Doria, the group tested and assessed the various products and discussed their application for different purposes.  

Being an expert on the topic of natural adhesives, Rossi Doria extensively explained his research into the bloom strength of animal adhesives. Bloom strength, also known as gel strength, is measured in bloom grams (gB), and equals the force required to make a specific depression into a gel sample. Plainly put, it measures the hardness of a gel or gelatine sample. Commonly applied within the food industry to manufacture galantine i.e., the bloom strength is not researched enough within the conservation field.Although, it is known equally to conservators and manufacturers of conservation products, little is known about its usefulness for conservation treatments. In fact, there is a lack of knowledge within the field about how to confidently use this property in practical terms.  
Rossi Doria’s research is filling this gap. His innovative perspective on this topic is helping conservators to understand more fully consolidation process from the perspective of natural adhesives, while using the bloom strength.  
Discussing the properties and qualities of these adhesives and gels in the context of the current conservation market, engaged all participants, and fine-tuned their knowledge on current availabilities and possibilities for this kind of treatment options.   

Traditional methods applied with innovative insights  

Another highlight of the programme consisted in studying the Italian methods of linings, which vary from region to region. Chiara Merucci (Head of Painting Conservation Palazzo Barberini) presented the history and materials of Italian glue-paste linings. During a tour through the Barberini and Corsini collections, Merucci and Alessandro Cosma (head of collections) shared fascinating facts about the artworks and their techniques.  

Having the opportunity to learn about the fundamentals of traditional Italian lining, first hand and combine them with new insights, truly made this workshop unique. Looking back at these two intensive weeks in Rome, Joanna feels grateful to have gained new knowledge on water-based systems in relation to re-lining. She is confident that her newly acquired skills will be usefully put into practice at SRAL and benefit many paintings conservation projects.  

Special thank you to Matteo Rossi Doria (Senior Painting Conservator C.B.C.) and Chiara Merucci (Head of Painting Conservation Palazzo Barberini) for organising the event and sharing so generously their extensive knowledge on Italian painting and conservation methods. Also, great thank you to the Getty Foundation and Conserving Canvas initiative for supporting this project.  

More about this project: 

https://www.barberinicorsini.org/en/evento/palazzo-barberini-conserving-canvas-2022/ 

https://vimeo.com/738522770 

Capture picture 1: Bacchus and Ariadne, painting after the liningtreatment Credits: Palazzo_Barberini_Conserving_Canvas_2022_Bacchus_and_Ariadne© Matteo Rossi Doria 

Capture picture 2: Raising lining canvas stretched on the working loom 
Credits: Palazzo_Barberini_Conserving_Canvas_2022_during_workshop_2© SRAL 

Capture picture 3: Tensioning the lining canvas on the working loom 
Credits: Palazzo_Barberini_Conserving_Canvas_2022_during_workshop_5©SRAL 

Capture picture 4: Bacchus and Ariadne, painting before the lining treatment
Credits: Palazzo_Barberini_Conserving_Canvas_2022_painting_before_lining_workshop©SRAL

Capture picture 5: Participants and hosts of the workshop with the guest visitor 
Credits: Palazzo_Barberini_Conserving_Canvas_2022_participants_workshop© Palazzo Barberini 

Capture picture 6:Bacchus and Ariadne, detail showing the back of the painting. Old lining detaching from the original canvas 
Credits: Palazzo_Barberini_Conserving_Canvas_2022_during_workshop_3© SRAL   

Capture picture 7: Local interleafs reinforcing the small holes in the original canvas
Credits: Palazzo_Barberini_Conserving_Canvas_2022_during_workshop_6©SRAL