Introduction

The symposium held at Yale University in October 2019 grew out of the Getty Foundation’s Conserving Canvas initiative, which, through a combination of practical workshops, publications and research support, and expert meetings, aims to evaluate and foster the structural treatment of paintings on canvas (fig. 0.1). The symposium was planned with the 1974 Greenwich Conference on Comparative Lining Techniques,¹ the last international conference to be held on this subject, very much in mind. At that event, conservators from institutions and in private practice demonstrated a wide range of techniques, both innovative and traditional, and in doing so raised some fundamental questions that are still central to our thinking and decision-making process in planning structural treatments. In the forty-five years since, however, the options for lining and alternatives to lining have expanded. The new options are drawn from a variety of sources: advances in the materials industry, with the production of synthetic adhesives and textiles and the introduction of nanotechnology; new research into the mechanical behavior of laminate structures; and the resourcefulness of conservators who take an innovative approach to their work. Concerns at the forefront of the field in 2019 also included environmental sustainability and a heightened awareness of the benefits of a global perspective on painting conservation.

The timeliness of the Conserving Canvas initiative and the conference is clear. In the planning stages, it was thought the sessions would be held on Yale’s West Campus, where the conservation studios and the Institute for the Preservation of Cultural Heritage are located. High demand quickly dictated a move to the more spacious auditorium at the Yale Art Gallery. The auditorium was filled to capacity with over 370 attendees from more than twenty-five countries, likely the largest gathering of painting conservators ever convened (fig. 0.2). The amount of interest in the topic was also mirrored in the international response, as reflected in the number of papers presented by conservators from more than twenty countries.

The impact of the postprints of the 1974 conference was even greater than that of the conference itself, as they not only presented to a much wider audience the different approaches introduced there but also questioned previously held assumptions. While the conference provided the opportunity for conservators to compare lining techniques, with a focus on practical workshops, the necessity of lining as a preservation measure was ultimately called into question. For many, the most perceptive and significant paper was the opening presentation by Westby Percival-Prescott, “The Lining Cycle,” in which he demonstrated how artists’ techniques of a certain period affected the response of those paintings to particular lining practices of the time, usually evident many years later when those paintings were deemed to require lining.² Percival-Prescott’s paper, after reviewing different lining techniques, called for research into methods that might prevent the necessity of lining (see Stoner in this publication). In effect, a call for historical research and a minimalist approach was made.

With this context in mind, the call for papers for this symposium, made in September 2018, announced, “The symposium will address historical approaches to and theories of the structural conservation of canvas paintings; current methods, materials and research, both practical and scientific; and the challenges facing the structural conservation of modern and contemporary works.” This reflected, in the view of the Advisory Committee,³ developments and concerns in the structural treatment of works on canvas today. The response to the call for papers was much larger than expected, and the proposals submitted guided the committee to choose the sections laid out in these postprints.

While Percival-Prescott’s paper was unique in providing a historical review in 1974, at the 2019 symposium historical research played a very significant role. The recent research into contemporary documentary sources, discussed in contributions by Angela Cerasuolo, Matteo Rossi-Doria, and Ana Calvo et al., attest to considered practices dating back to the eighteenth century and earlier. In many cases, written sources can be linked to surviving treatments, often demonstrating the unexpected longevity of linings carried out with natural materials. A strong case is made for the use of natural materials—both for their low toxicity and their performance over time. On the other hand, assumptions about the stabilizing hydrophobic attributes of wax-resin treatments were called into question by new research, as can be seen, for example, in the work by Emilie Froment. A divide on seeking flexibility (as in mist-lining) or rigidity (as demonstrated in Lynne Harrison’s paper) in a lining or lining system emerged, which also represented the trends of research on lining procedures and the mechanical behavior of the composite structure of paintings since the Greenwich conference. The fact that many of the practical and philosophical divides in structural practices still fall along geographic lines speaks to the sustained, deep roots in historical treatment practices.

Another theme that emerged at the Yale conference was an emphasis on the history and treatment of collections as a whole, as well as forward-looking preventive care of collections. Here, too, the role of past and ongoing research was evident, although perhaps not always carried over into practice. Increased levels of documentation also allow for the examination and analysis of more data, mostly focused on collections and their treatment histories. The greater attention to documentation has enabled reviews of institutional practice—which, when the data are extensive enough, reveals trends, as evidenced in the contributions by Nicola Costaras and Lauren Bradley and Josh Summer. A series of case studies covered the treatment of works large and small and highlighted the significant attention paid to local interventions, which demonstrate conservation’s continuing ability to adopt and adapt existing techniques and equipment from other fields, such as textile conservation, imaging technology, and mechanical engineering. Papers included research using samples of significant natural aging and showed the ongoing embrace of new materials—both from other fields and those specifically developed for conservation. The audience was introduced to Hannah Flock et al.’s “Winnie” for the application of glue in tear mends, for example, as well as the adhesive meshes developed by Mona Konietzny et al.

Threaded through all of these topics was the ongoing question of definitions, of finding a common vocabulary to describe—with as much precision and accuracy as possible—what conservators see and do. This is especially critical in order to exchange philosophies, methodologies, and techniques with an international community that has grown out of a variety of historical traditions and practice in vastly different climates. To that end, we have included a glossary based on the one published in the 1974 preprints. Terms no longer in use have been deleted and terms that have become current have been added. It is our hope that this revised glossary reflects developments since 1974 while also attempting to define terms that can be used universally. Finally, around the margins but clearly moving to a central position is the question of sustainability in all its various forms. Indeed, here is a term in need of definition and common understanding.

One part of the conference that is not available to the reader of these proceedings is the day devoted to practical demonstrations—“sandbox sessions”—that provided the opportunity for experiential learning (fig. 0.3). Expert contributors led sessions on historical reconstructions, innovative tools and equipment, hands-on mechanical demonstrations, and localized tear mending. It is the continued refinement of established practice, as well as development of new, more effective practices, that these sessions represent, and to which we believe these proceedings will be an ongoing contribution.

None of this would have been possible without the support of a large network of our generous, capable colleagues. First, thanks are owed to the rest of the symposium Advisory Committee: Alan Phenix, Mikkel Scharff, Antoine Wilmering, and Christina Young. At Getty, thanks also to Joan Weinstein and Allison Reilly. At Yale, thanks go to Stephanie Wiles; Henry J. Heinz II, director of the Yale University Art Gallery; and Courtney Martin, director of the Yale Center for British Art, for their support, contribution of space and resources, and hospitality shown to the participants. The conference would not have been possible without the ongoing efforts of Laurie Batza, Beth Bolen, and Elizabeth Williams at the Yale Institute for the Preservation of Cultural Heritage. Also, thanks to the Yale Conferences and Events staff, especially Shannon LeGault, who arranged two meals a day and warm welcomes for our 370 participants. The Avangrid Foundation provided critical funding support for presenters and attendees from Spain, and our special thanks go to Nicole Licata Grant. The program books were designed by Stephanie Bedoya with the assistance of Yale University Art Gallery designer Chris Sleboda, who also designed the tote bags for the participants. Advertising support from Willard Conservation Products, Everett Fine Art, and Getty Publications made the program books possible. At the Yale University Art Gallery, thanks are owed to Molleen Theodore, Liz Harnett, Mark Paturzo, and Roksana Filipowska. Many Yale University conservators, conservation fellows, and interns contributed to the success of the symposium, from hosting guests and providing directions to assisting in sandbox sessions and hanging posters, and too many other supportive roles to mention. Our deep thanks for this to Irma Passeri, Kelsey Wingel, Mark Aronson, Jessica David, Anne Gunnison, Olav Bjornerud, and Beth Godcher. We are also deeply grateful to Rachel Barth, Leslie Tilley, and Dianne Woo for their support, dedication, and patience as they edited and proofed sixty-three papers. We hope that this publication will be of great value to the international conservation community for years to come.

1. The postprints were published as Villers 2003b. ↩︎

2. Many of these effects changed the appearance of the paintings. These changes to the structure, topography, and other attributes of the painting have been described in various ways in the conservation literature. Most importantly, though, a consensus emerged that these changes compromised the aesthetic integrity of the painting, bringing aesthetic discussions of the surfaces of paintings to the fore as well as discussion of technical matters. ↩︎

3. The Advisory Committee consisted of Jim Coddington, Ian McClure, Alan Phenix, Mikkel Scharff, Cynthia Schwarz, Antoine Wilmering, and Christina Young. ↩︎