The Restoration of a Masterpiece: Five Things You Didn’t Know About Quinten Massijs’ Altarpiece of the Joiners’ Guild

When the restoration began in 2021, a phased approach was adopted. This was partly driven by practical considerations such as planning, budget, and the relocation of the restoration studio, but above all by the structure of the altarpiece itself. Because Quinten Massijs also worked in phases, the panels display noticeable stylistic differences.

The side panels, for example, are more flamboyant in style, recalling the early 16th-century Antwerp Mannerists. Several striking faces are clearly inspired by drawings by Leonardo da Vinci. The central panel, by contrast, draws more strongly on 15th-century models by Rogier van der Weyden. It therefore made sense for the conservators to work from the outside in, allowing them to follow Massijs step by step through his artistic process.

There is much to say about Massijs’ technique. Although he was active several generations after Jan van Eyck and their approaches differed in many respects, conservators and art historians continue to place the two masters on a comparable level. Massijs’ great strength lay in his ability to achieve contained emotion and richly decorative surface effects with minimal means. He worked with remarkable assurance and swiftness, using relatively little material — something that is scarcely noticeable at first glance. His touch was exceptionally refined, particularly in the rendering of faces, here especially those of female figures.

Preliminary research quickly revealed that the altarpiece’s treatment history had been problematic over the centuries. Testimonies and archival records from the 17th century already point to the poor condition of the work, followed by what is believed to have been heavy-handed cleaning at some point over the following 150 years. Although conclusive evidence is lacking, conservators were able to determine that the faces and figures in particular had been treated too aggressively. The aim was presumably to increase luminosity, but because of Massijs’ subtle painting technique this intervention left its traces.

From the late 19th century onwards, the documentation surrounding the altarpiece becomes clearer and more consistent, although major interventions remained limited. In the 20th century, issues such as flaking and peeling paint, as well as yellowed varnish layers, were reported. The subsequent—and final—treatment prior to the recent restoration was confined to minimal retouching using soluble materials and the application of a new varnish layer. A thorough restoration was required.

It has long been known that the triptych has led an eventful life. In 1533, it narrowly escaped a fire in the Church of Our Lady and, some thirty years later, the Iconoclastic Fury. After this, it changed owners and locations several times. The recent restoration has made it possible to reconstruct this journey visually and to trace the life story of the work in greater detail.

One striking example is the alteration of its shape. Originally, the altarpiece had a wavy top, as was customary in the early 16th century. Restoration research has shown that this was later straightened by the addition of an extra panel, probably to give the work a more secular appearance. Coats of arms and urban elements appeared on this added section, largely attributed to Michiel Coxcie. This intervention coincided with the move to Antwerp City Hall. On the advice of Maarten de Vos, the city purchased the work for five times its original price, thereby saving it from destruction during the Calvinist period around 1580.

After several years, the triptych returned to the Cathedral of Our Lady. Two hundred years later, following the French occupation, it entered what would become the early KMSKA collection. Unfortunately, the structural modification mentioned above caused damage and ultimately led to the loss of the original upper edge.

While the side panels depict scenes of their martyrdom, the exterior panels present John the Baptist and John the Evangelist as stone statues set within niches. This technique is known as grisaille, a term referring to the use of shades of grey and brown to create the illusion of sculptural relief on a flat surface. The grisailles on the Altarpiece of the Joiners’ Guild represent an exceptionally refined application of this subtle interplay of light and shadow. They demonstrate how Massijs, alongside artists such as Jan van Eyck, also embraced this pictorial tradition.

Initially, the restoration of the exterior panels was intended to be limited to preventive cleaning and the application of a new varnish layer. During the treatment, however, it became apparent that these panels had not been thoroughly maintained for at least 150 years. From the 20th century onwards, altarpieces were generally displayed in an opened position, leading to the neglect of their exterior surfaces. Yet this notion of a triptych as a static object runs counter to its original function. In the Low Countries in particular, such altarpieces were conceived as movable works. In fact, they were often opened only on Sundays and feast days as part of the liturgical ritual. 

Another discovery relates directly to the function of the altarpiece: conservators identified traces left by burning candles at the bottom centre of the work. While these marks might be considered damage, they also tell an important story. Altarpieces were positioned behind the altar, where candles were lit, shaping both the atmosphere and the lighting in which the work was originally experienced. Yet among art historians and conservators, there has long been a tendency to remove such traces of use.

In the case of the Altarpiece of the Joiners’ Guild, a middle ground was chosen. First and foremost, the candle marks were carefully documented and photographed. Any retouching was then carried out using soluble materials, ensuring that these traces are not permanently lost.

This case forms part of a broader debate about the presentation of religious art as static and purely aesthetic objects. A related example is the invisibility of the exterior panels when an altarpiece is permanently displayed in the open position. The restoration therefore offers a compelling starting point for reflection on the balance between artistic and ritual significance in contemporary restoration and exhibition practice. The possibility of a movable structure that would allow the altarpiece to be displayed in all its aspects in the future is not excluded.

Has your curiosity been sparked and would you like to learn more about the Altarpiece of the Joiners' Guild? On 3 February 2026 at 3 p.m., there will be a curator talk in the museum about the artwork with Samuel Mareel (curator of the 15th and 16th centuries).