Restoration and research of the upper register of the interior of the Ghent Altarpiece
After the treatment of the closed polyptych (2012-2016) and the lower register of the opened polyptych (2016-2019), the third phase of the restoration of the Ghent Altarpiece (1432) is now ongoing. The upper panels of the monumental artwork by the Van Eyck brothers moved from Saint Bavo's Cathedral to the Museum of Fine Arts (MSK) in Ghent. KIK-IRPA experts carry out in-depth research and the challenging restoration over the course of three years.
Church administration of Saint Bavo’s Cathedral, Ghent
The upper register and its challenges
In 2012, the Royal Institute for Cultural Heritage initiated a large-scale restoration campaign of one of the world's most iconic works of art: the Ghent Altarpiece by the Van Eyck brothers (1432), which was created for Saint Bavo's Cathedral in Ghent and is still kept there. The treatment of the polyptych is carried out in three phases. The seven panels of the upper register of the polyptych are now up for a specialised treatment aimed at preserving and valorising the entire artwork of the Ghent Altarpiece in a homogeneous, safe condition.
The upper register of the open altarpiece differs from the rest of the masterpiece in two important ways. On the one hand, it is notable for its technical and stylistic diversity. It combines three large central figures (Mary, the Deity and John the Baptist) in a complex setting with groups of singing and music-making angels on either side against a blue sky and, finally, large free-standing naked figures, Adam and Eve, on the sides. On the other hand, the state of preservation of the panels varies greatly, as they have not undergone the same treatments in the past and have not all been preserved in the same conditions at all times.
The three central panels, the enthroned Virgin Mary, the enthroned Deity and the enthroned St. John the Baptist, were confiscated in 1794 and taken to Paris to remain at Musée Napoléon until 1815 before being returned to the cathedral in 1816. The conservation issues of these panels are largely similar to those of the first and second phases of the project. Many retouches and overpaints are present.
A major restoration challenge are the press brocades, present in the background of the three central panels. They are thin, rectangular leaves of tin foil, which are pressed into an engraved mould, creating relief. After this, they are gilded and painted. They mimic expensive, exclusive silk fabrics or brocades. Their complex composition with diverse materials, each with their specific degradation issues, makes their restoration especially intricate.
The side panels consist of Adam and Eve and the singing and music-making angels. These panels equally have their own specific material history and conservation issues. The singing and music-making angels, along with the other side panels of the altarpiece, except Adam and Eve, were sold to an art dealer in 1816. They eventually ended up in the royal collection in Berlin in 1821. In 1894, they were sawn in half in their thickness and cradled to allow all the painted surfaces to be displayed simultaneously. After World War I and the Treaty of Versailles, the panels were returned to the cathedral in 1920 as compensation for war damages. The paint layers of these panels show many drying cracks. Many compositional changes were made in the original paint layers.
The panels of Adam and Eve remained in Belgium and were placed in the Royal Museums of Fine Arts of Belgium (KMSKB) in 1861. In 1921, they were given in perpetual deposit to Saint Bavo’s Cathedral, and from then on the Ghent Altarpiece was again displayed in its entirety in the cathedral. The frames and wooden supports of the panels with Adam and Eve were treated during the first restoration phase. The large area of overpainting constitutes a major challenge during phase 3.
During the third phase, the team will stabilise the paint layers and wooden supports of the upper register of the Ghent Altarpiece and restore the pictorial balance between all the panels. Initially, the non-original layers of varnish are removed and the existence of 16th-century overpaints and whether they can be removed to expose the original work by the Van Eyck brothers, are investigated. Lacunae in the painted panels will be filled and accurately retouched. The conservators-restorers will recover the subtle nuances and details of the original. To the naked eye, the Ghent Altarpiece will look like a beautiful whole. On the Closer to Van Eyck website, visitors can zoom in on the altarpiece and the retouches will be detectable there. Finally, the retable will receive a new coat of varnish to achieve a homogeneous result. The wood of the panels and the frames of the upper register will also be treated. The separation of hands between Hubert and Jan van Eyck, one of the great mysteries of art history, will be further examined in depth. The research and the sustainable restoration of the altarpiece make a crucial contribution not only in terms of aesthetics, but also in terms of the history of painting techniques in the late Middle Ages in general and those of the Van Eyck brothers in particular.
"Our expertise in the complex issues surrounding the Ghent Altarpiece, both in terms of execution and scientific research, is unique. It enables us to guarantee the material and visual coherence of the entire altarpiece after restoration. The treatment of these very diverse panels, with beautiful life-size figures and diverse problematics, is a real challenge."
A pinnacle of cooperation
For the third phase of the restoration campaign of the Ghent Altarpiece, i.e. that of the upper register in open position, the interdisciplinary team of KIK-IRPA is once again in place. It consists of highly specialised conservators-restorers, chemists, physicists, technicians, photographers and art historians, whose experience during the first two phases ensures the homogeneity of the project. The substantial and profound interdisciplinarity of KIK-IRPA already constituted the foundation of the two previous restoration phases and has been praised both nationally and internationally.
The core team* of conservators-restorers is complemented by internationally recognised experts in the conservation-restoration of gilding and polychromy and, for this third phase in particular, of press brocades from the 15th and 16th centuries.
*Dr Hélène Dubois, Kathleen Froyen, Dr Griet Steyaert, Marie Postec, Nathalie Laquière, Françoise Rosier, Laure Mortiaux
The project is also once again supervised by an international and interdisciplinary commission of experts (photo below) and stakeholders from the Flemish and Belgian heritage sector.
A three-phase treatment
The already completed phases of the restoration campaign – the first of the closed polyptych (2012-2016) and the second of the lower register of the opened polyptych (2016-2019) – already led to stunning discoveries. It soon became apparent in 2012 that the condition of the paintings was more complex than expected. As a result, Jan van Eyck's original painting, partially hidden under overpaintings for five centuries, was rediscovered and exposed. Of particular note was the revelation of the original lamb on the central panel in 2018. The 16th-century pictorial layers were carefully removed to make way for Van Eyck's 15th-century depiction, which turned out to look very different.
The recovered pictorial quality of the paintings exceeds all expectations. KIK-IRPA experts were further able to distinguish the hands of Jan and Hubert van Eyck, prove the authenticity of the inscriptions with date and attribution on the frame, and reveal the beautiful stone imitations on the frames, which illusionistically embed the paintings in an architectural setting. Interesting finds are also expected for the third phase, which is likely to be completed in spring 2026.
"With the research, treatment and publications of the two previous phases, KIK-IRPA and its partners established a milestone in the knowledge of the paintings of the Van Eyck brothers. With the latest technologies and an interdisciplinary team, the panel paintings were subjected to an in-depth study that made it possible to distinguish, for the first time, the underdrawing, the contribution of each of the Van Eyck brothers, and the various overpaints. The search continues in the final phase of the restoration. On the seven upper panels of the interior, issues that have not been known to date will undoubtedly come to light."
The conservation treatment of the Ghent Altarpiece is a project commissioned by the church administration of Saint Bavo's Cathedral in Ghent. The file was put out to tender at the European level and again awarded to the Royal Institute for Cultural Heritage (KIK-IRPA) of Belgium. 80% of the funding for this phase comes from the Flemish government, of which 40% from the Department of Culture, Youth and Media (Topstukkenfonds) and 40% from the Flanders Heritage Agency (total: €1,500,000). The remaining 20% will be borne by the church administration and is co-financed by the Baillet Latour Fund. The research by KIK-IRPA, with contributions from the universities of Ghent and Antwerp, is additionally supported by the Gieskes-Strijbis Fund (Amsterdam).
As with the first two phases of the restoration of the Ghent Altarpiece, the public is able to follow the treatment closely at the workshop at the MSK in Ghent. At Saint Bavo’s Cathedral visitor center, visitors can admire the restored panels of the Ghent Altarpiece and several other authentic art treasures in all their splendor.
Want to know more?
KIK-IRPA discloses the results of the research on its website and on Closer to Van Eyck (in collaboration with the Getty Foundation) where you can zoom in on high-resolution images of the Ghent Altarpiece and all other paintings by Jan van Eyck and his workshop. The website operates on the open access principle and is aimed at both researchers and the general public.
Publications, lectures at international colloquia, guest lectures in universities and presentations for the general public of art lovers will also follow during and after the restoration campaign.
The first two phases of the restoration have already been extensively covered in The Ghent Altarpiece. Research and Conservation of the Exterior (2020) and The Ghent Altarpiece. Research and Conservation of the Interior: The Lower Register (2021).
Images: Saint Bavo's cathedral, Ghent, www.artinflanders.be, photos KIK-IRPA, Brussels
"We are proud to once again exhibit our interdisciplinarity for the final stage of the treatment of the Ghent Altarpiece. Each phase of conservation-restoration is accompanied by extensive research by various teams from our Institute as well as external partners; research that we document in great detail and share with the public through various channels. As always, KIK-IRPA strives to maximise the sharing of knowledge and the disclosure of innovative scientific data that we put at the service of the heritage sector and the wider heritage community."
The textile machines at the Museum of Industry in Ghent are the oldest in the world
For the first time, KIK-IRPA has researched historical machines from Belgium's industrial past. It involved the Mule Jenny and the Twine mill, two centuries-old large textile machines from the Museum of Industry in Ghent for spinning and twisting threads. Our specialists were able to confirm that the two masterpieces are the oldest of their kind in the world.
