Art & Technology

Dendrochronology and infra-red photography are giving surprising results among Netherlandish paintings at the Metropolitan Museum

Can a human eye beat the latest technology?

New York

It’s a rivalry which can only become fiercer: the connoisseur’s eye versus technology’s bag of tricks. The Metropolitan Museum has been examining some of its most treasured paintings with the aid of the latest technology, and it has come up with a result which confounds the hitherto accepted history of art. One of its most important early Netherlandish paintings “Christ appearing to His mother”, formerly thought to be by Rogier van der Weyden, was downgraded by technology to a workshop copy a decade ago. Now a different scientific process has shown that, instead of being an early fifteenth-century painting, it in fact dates from the end of the century, which calls into question all the assumptions about artistic development on which traditional art history has been based.

The major tool in these discoveries has been the use of infra-red reflectography to read underdrawing. Developed by the Dutch physicist J.R.J. van Asperen de Boer, it employs a camera equipped with an infra-red vidicon that allows an image of a small section of a panel to be transmitted to a television screen. It will penetrate most pigments, with the exception of those that are carbon-based, underdrawings being in charcoal or carbon-based ink. It surpasses the use of infra-red photography in its clearer rendition of the various “handwritings” of panel preparation. In tandem with dendrochronology, the dating of wooden panels by tree-ring analysis (the current leading expert in which is Peter Klein of Hamburg University), these new techniques have enabled scholars to attribute, place and date early paintings more accurately, though often new questions arise from their findings. Underdrawing analysis is, however, not always conclusive, nor indeed always possible. Curator Maryan Ainsworth of the Metropolitan Museum is quick to note that, “The thorny problem of underdrawings and workshop practice in, for example, the works of Lucas Cranach and his circle is not easily resolved through underdrawing analysis, since in many cases, the picture was drawn in with a non-carbon substance, like iron-gall brown ink, that is not penetrated by infra-red, and is invisible on the reflectogram screens. It is maddening, since so often you can see traces of underdrawing on the painting’s surface just with the naked eye!”

One of Ainsworth’s and her colleagues’ most astonishing findings has been the downgrading of “Christ appearing to His mother” by a follower of Rogier van der Weyden. Acquired by bequest in 1921, it used to be considered one of the Metropolitan Museum’s greatest early Northern paintings. It, and two cut-down companion panels in the Capilla Reàl, Granada, were thought to be originals by van der Weyden of an altarpiece that had belonged to Queen Isabella of Spain, while another version, in the Gemäldegalerie, Berlin, was dismissed as a workshop copy. This view held until 1991-92, when Berlin’s curator of early Netherlandish painting, Rainald Grosshans, published his findings on the underdrawing of the Berlin version, which unmistakeably showed Rogier’s characteristic hook-ended drawing style, with several changes in composition. Then subsequent research by Maryan Ainsworth revealed the mechanical underdrawing of the Met’s panel, done without changes, and probably taken from a pattern or tracing. “This wasn’t conclusive in itself”, says Ainsworth, “but Grosshans correctly noted that the perspective in our painting had been subtly altered, mostly in the architectural surround, to conform with a one-point perspective, which is a much later fifteenth-century development. What has made the re-dating definitive has been the dendrochronologist’s report which dates the panel to around 1485—some twenty years after Rogier’s death”.

Ainsworth has just published her findings along with another study of the Met’s “Adoration of the Magi” formerly attributed to Jerome Bosch, and now to a later follower, in Volume 27 of the Metropolitan Museum’s Journal (see p. 19). The reattribution of the panel, Ainsworth admits, is not nearly as unnerving as its re-dating. “The entire concept of artistic licence and innovation, on which we put such a high premium these days has nothing to do with the way much early Northern painting was created. The medieval craftsman tradition was such an important part of Northern painting. We don’t really comprehend how rigorous the training in the guild system was. Artists could make these perfect copies, not just reproducing the composition, but even the way it was painted, and the handling of the paint. Jellie Dijkstra has published some telling information she discovered in Belgian archives: around one-third of all the fifteenth-century commissions and half of the sixteenth-century commissions request a copy of one kind or another. Copies were not denigrated; in fact, it was nearly as important to own an image that had a certain spiritual value and worth as it was to have something new. The San Francisco Museum is loaning us their beautiful Dirck Bouts ‘Madonna and Child’ that was done from the same cartoon or pattern as ours, the main difference being that theirs has a brocade background and ours is plain. There is a version in the Bargello even closer to ours, and I’d love to have the opportunity to examine and show all three together”.

Another future project, for 1994, is an exhibition at the Metropolitan of the works of Petrus Christus, which Ainsworth is organising. This exhibition will be exceptional in that it will be a nearly complete overview of his output. The fragility of most Early Netherlandish panels means that most museums will refuse loans save for a very good reason. Most recent early Netherlandish shows have therefore tended to be closely focused, either with very few outside loans (as with the National Gallery, Washington’s 1992 show around its Gerard David “St Anne altarpiece” which temporarily reunited the gallery’s three central panels with its predella panels from Edinburgh and Toledo, Ohio), or organised as in-house “dossier” shows, as with the 1991 Joos van Cleve exhibition at the Louvre, organised by Cècile Scaillierez, who is preparing an in-house Hans Memling show for 1994. A major Memling show, organised by Dirck de Vos for the Bruges Museum, is planned for the same year.

In the meantime, with funding support from the Kress Foundation, Molly Faries of Indiana University, Bloomington, is preparing to enter her extensive archive of over 10,000 infra-red reflectograms into a database. Covering artists from Byzantine times to the nineteenth century, it should allow scholars to establish underdrawing styles for individual painters.

Originally appeared in The Art Newspaper as 'How good is an eye?'