Jan van Eyck’s depiction of nature and natural phenomena is without equal. It is true that some of his contemporaries excelled in painting particular facets of nature to such a degree that they actually surpassed him in fidelity: Pisanello (c. 1395–c. 1455) and his studies of birds, for example. Yet none came close to matching the comprehensive scope or precision of Van Eyck’s observation of the natural world. His hard-to-fathom realism has already been discussed in numerous studies, both en passant and in detail. I will limit myself in this essay to the scientific accuracy of the painter’s representation of nature and natural phenomena. The picture presented here is inevitably incomplete, for apart from the fact that Van Eyck’s oeuvre offers an inexhaustible wealth of detail, we need to realize that it has not survived intact. Karel van Mander (1548–1606) noted that he painted ‘from life’ (nae t’leven) and that it took him a great deal of time to paint his landscapes. And we know from Bartolomeo Fazio, for example, that the Lomellini Triptych contained an elaborate background landscape, even though the painting has disappeared without trace. Bearing in mind that our knowledge is fragmentary, this essay aims to draw a summary sketch of Van Eyck’s vision of nature, based on a combined scientific and art-historical analysis of specific natural phenomena. ‘Vision’ is intended here in both the literal sense of his observational powers and, insofar as possible, metaphorically too: how does nature fit into the way he conceived his art? Did Jan van Eyck view the world with different eyes from many of his colleagues? His acute observation of rocks, clouds, the moon and the silhouettes of birds in flight is unprecedented; for the most part, these are facets of nature to which painters before Van Eyck paid little heed, and that were not studied or painted in such detail by his contemporaries either. All the same, his powers of observation were not boundless, and this too will be highlighted as a corrective to his otherwise undisputed genius. Van Eyck’s paintings were not, moreover, mirrors of reality, or at least only partially so: they drew on a realism suffused with pictorial strategies. This is a fragmentary realism, manipulated and laden with symbolism.8 Van Eyck adjusted his observation of nature to his painterly vision of it, both consciously and unconsciously, and also to some extent out of necessity or pragmatism, given that it is plainly not possible to study and paint the entire natural world in extenso.

The outer panels of the Ghent Altarpiece had been overpainted to a considerable extent. The virtuosity of the Eyckian technique and aesthetics remained hardly visible. And yet, this had never been observed before the start of the conservation treatment. By removing the overpaint, the tonal richness and the coherent rendering of light and space once again came to the fore. Especially the suggestion of volumes and the spaciousness of the ensemble gained strength because of the virtuoso play of deep shadows and bright light accents, and not in the least because of the surprising trompe-l'oeil effect of the frames conceived as a stone framework. Or to put it in the words of the comments of one of the experts, dr. Maryan Ainsworth: The paintings live and breathe again in the time of the Van Eyck brothers. The sharp observation skills, the quick, accurate execution, the knowledge, curiosity and ingenuity about all the things that are depicted, are now unveiled after centuries. The profit for the knowledge of and further research into the essence of Eyckian aesthetics is considerable. And finally there is the discovery that the much-discussed quatrain was applied simultaneously with the polychromy of the frames: a real 'coup de foudre' in the discourse of the current art-historical research! The subtleties of the Eyckian technique could also be mapped out in more detail. How the Van Eycks managed to keep the final result and the desired effect in mind during every phase of the execution, from imprimatura to finishing touch. The artists made a statement about the art of painting, giving ‘technique’ as such a new prominence. The Ghent Altarpiece may be understood at some point as a major showpiece for a highly sophisticated pictorial technique. We hope that this publication of the results of the research and conservation campaign on the exterior of the altarpiece can help future researchers to ask better questions. Questions, and answers, that may produce a more balanced picture of Van Eyck's techniques, methods and materials.

The recently discovered metalpoint drawing has convincingly been attributed to Jan van Eyck or his immediate environment.1 Measuring 254 x 187 mm, the drawing shows a large crowd of bystanders around the Crucifixion. It bears an obvious relationship to the left wing of a diptych by Jan van Eyck, now in the Metropolitan Museum of Art in New York.2 A technical examination of the sheet may shed some light on the genesis of this drawing in particular, and workshop processes in Jan van Eyck’s studio in general. Although the drawing has recently been the subject of technical investigations (see the appendix in this volume), there is a need to address a number of insufficiently understood material aspects

Toon De Meester, Jan Dumolyn, Susan Frances Jones, Ward Leloup, Bernard Schotte and Mathijs Speecke, ‘Meester Jans huus van Eicke. Jan van Eyck’s House, Workshop and Milieu in Bruges: New Archival Data’, eds. T.-H. Borchert, M. Martens and J. Dumolyn, Van Eyck. An Optical Revolution, exh. cat., Hannibal, Ghent, 2020, pp. 127-37.