The late discovery of Hubert’s work

It was common knowledge that Hubert had started the Altarpiece. A famous inscription (a quatrain: four verses) painted on its frames tells that Hubert began and that after his death [in 1426] his brother Jan took over and completed the work in 1432. It is not known when Hubert had started, nor was it known what part of the Altarpiece he had worked on. In how far he conceived the masterpiece is also unknown. When did he stop due to health reasons? From Master Hubert to Master Jan, the painting took many years to be completed. This can explain why we see damage between the two periods, and it helps to understand the complex building up of layers. The structure of a painting at that time, if done by one single Master, consists in superimposing several layers, more or less transparent. When an artist superimposes his version on another painter’s painting, it becomes even more complicated. A transparent layer (generally a varnish) can isolate two successive paintings, but a transparent layer or a varnish can sit between two original layers. This situation has been described in the portrait of Margareta Van Eyck, in the Groeningemuseum in Bruges. This draws the attention to the danger of relying on a varnish to separate layers. The danger is that the layer above the varnish is considered by the restorer merely as an ‘overpainting’. To complicate the matter even more, let us remind ourselves that numerous repairs had taken place on the Ghent Altarpiece, some already in very early times. This gives an idea of the challenges that the restorers of the Ghent Altarpiece had to confront.