Reviewed by Susanna Wyse Jackson
Hosted by the Polish national committee in Kraków on the 9 and 10 July 2026, the 13th Forum for the Conservation and Technology of Historic Stained Glass brought together conservators, scholars, technicians, and curators with an interest in the materiality and conservation of stained glass (Figs. 1 and 2). The theme of the Forum, ‘Historical Techniques and Approaches to the Conservation and Restoration of Stained Glass’, prompted a wide-reaching and diverse range of submissions, collectively oriented towards the impact of historic research and conservation methodologies on our understanding and care of stained glass today. The result was a compact yet impactful programme of papers.
There were several striking complementarities within the well-curated selection of talks. For instance, the spontaneous browning of green enamels was explored by Teresa Palomar, while a similar phenomenon in contemporary blue enamels was identified and discussed by Emma Groult and Bénédicte Lacheré. It was encouraging to discover similarly interlinked strands of enquiry connecting my own paper, which reassessed current cold painting strategies in use at York Minster, and the work of Silvia Silvestri, who presented on the conservation challenges associated with cold paint glazes (beveroni) used in Italian restoration campaigns of the nineteenth and twentieth centuries. Several papers explored the histories of long-standing stained glass institutions, namely the family-run Atelier Mestdagh in Ghent (Katrien Mestdagh); the Laboratoire de Recherche des Monuments Historiques (Barbara Trichereau and Claudine Loisel); and the conservation department at Cologne Cathedral (Katrin Wittstadt and Ulrike Brinkmann), prompting us to reflect on the previous generations of conservators and craftspeople to whom we owe a great deal, and whose legacies both inspire us and challenge our ways of thinking about conservation in the twenty-first century.
The programme balanced broad thematic overviews with case studies that shone a spotlight on specific artists and their methods. For instance, two papers offered regional restoration histories, providing insightful explorations of conservation practices in nineteenth-century Switzerland (Katrin Kaufmann and Sophie Wolf) and nineteenth- and twentieth-century campaigns in Portugal (Alexandra Rodrigues). Narrowing our focus, we also learned about the workshop materials of Portuguese artist Ricardo Leone (Carla Machado) and the glass engraving techniques of Argentinian artist Atilio Boveri (María Paula Farina Ruiz).
Shifting away from the people and institutions underpinning our sector, other speakers directed our attention to materials and methods, with topics including: the development of flat glass production (Michael Brückner); the history, materiality and ethics of epoxy resin use in stained glass conservation (Christa Heidrich and Markus Kleine); high-resolution 3D surface scanning of stained glass, both in and ex situ (Ruth Tenschert and Paul Bellendorf); and the value of collaboration with contemporary stained glass artists in the rediscovery of historic painting techniques (Margot Steurbaut). Similarly, the benefits of a collaborative, multidisciplinary methodology was further spotlighted by speakers Anna Santolaria and Charlotte Roden, whose paper on the discovery of a long-lost medieval window at Girona Cathedral (Fig. 3) illustrated with great clarity the instrumentality of a holistic approach to the interpretation of stained glass, its context, and the parameters of its conservation.
Beyond the standard programme of papers, our time was amply filled with a variety of other events, discussion fora, and site visits, not to mention a wonderful gala dinner held in the beautiful surroundings of the Krakow City Council building. The poster session, which directly preceded the dinner, offered a rich range of engaging discussion topics, including: the conservation of war-time protective filter paint (Martin Bucher); the origin of jewels and cabochons in the stained glass of Catalonia (Jordi Bonet and Ricard Bru); and a comparative investigation of the conservation philosophies underpinning the restoration work undertaken on the stained glass windows of two Polish sites (Sławomir Oleszczuk). Other posters offered exciting sector updates: Michael Brückner showcased the new Lamberts Restauro UV-IR glass designed for use in environmental protective glazing schemes, while a poster by Katrin Wittstadt and Ronja Lammers celebrated the launch of the new stained glass conservation degree programme at the Cologne Institute for Conservation Sciences, of critical importance for the future vitality of the industry in Germany following the closure of the Conservation and Restoration Department at the University of Applied Sciences in Erfurt in October 2024.
Visits to the Dominican Museum and the opening of the exhibition ‘Rejected/Forgotten: The Krakow Cathedral Stained-Glass Windows in the Period of Historicism’ at the Archdiocesan Museum (Fig. 4), as well as the option to join the Colloquium participants on the mid-week excursion to the Upper Silesian towns of Katowice (Fig. 5) and Gliwice, made this an invigorating and varied few days. The thoughtful integration of the Forum with the preceding Colloquium, both practically and conceptually, is to be commended, as it reflects in real terms the inseparability of art-historical stained glass research from discussions of the care, conservation and custodianship of these invaluable treasures.
Warm congratulations and many thanks to the Polish national committee for organising such a well-structured and enlightening programme of papers and events that truly encapsulated the dual nature of effective conservation enquiry, both back in time to acknowledge how far we have come, and forward into the future to imagine where we might go next. To paraphrase the inaugural remarks of Claudine Loisel (President, International Scientific Committee for the Conservation of Stained Glass) as she opened the Forum, the stained glass conservation sector is essentially one large, multinational team, all oriented towards a common goal, and this spirit of cooperation was alive and well throughout the Forum. As for myself, I left Krakow feeling informed, inspired, and suitably galvanised to return to the studio, pick up a cotton swab, and get to work.