Members of the P . R . B . were not attempting to recreate the early Renaissance tradition , but they were inspired by the inner luminosity of glazes , such as in the wondrous green gown worn by Giovanni Arnolfini ’ s bride . To achieve such effects they were scrupulous to apply their jewellike transparent colors over a bright white ground , which makes for a stained glass window effect , as seen for example , in the blue dress of the Mariana by Millais .
Although artists ’ manuals abounded 6 during the 19th century , the precise medium used in Van Eyck ’ s glazes was a mystery . In 1847 Charles Lock Eastlake , later first director of the National Gallery , published Materials for a History of Oil Painting , in which he pulled together as many ancient manuscript sources as he could , in order to trace the reason for the remarkable preservation of paintings over 400 years old . One of the most intriguing suppositions was that Van Eyck might have included amber varnish in his paint .
There is an understandable mystique to the idea that there was some “ secret ” ingredient . A practical reason is that plain linseed oil turns glazes yellow and won ’ t dry . Adding a resin to the oil makes sense because it can restrain the flow ( rheology ) of the oil and increase the depth of transparency and saturation of color . But how to prove this in Van Eyck ?
After World War II , the Allies recovered the Ghent Altarpiece from Hitler ’ s rape of the European cultural heritage . The Adoration of the Mystic Lamb has been called “ the most stolen painting in history .” After its recovery from a salt mine in Austria ( popularized in the movie The Monuments Men ( 2014 ), a collegium of experts was called to take careful stock of its condition , stabilize , and restore it . 40 ART CHOWDER MAGAZINE
Jan Van Eyck ( before ca . 1390-1441 ) detail from the altarpiece The Adoration of the Mystic Lamb , central panel 1430-1432 St Bavo ’ s Cathedral , Ghent , Belgium
One outcome of that project was the book L ’ Agneau Mystique au Laboratoire , published in 1953 7 , the first publication of a scientific study devoted to a single artwork and a landmark in the field of conservation science .
Through a series of microchemical analytical tests the team was able to identify , not only the pigments used by Van Eyck , but evidence of the binding media that held the pigment particles in place . The actual paint layers were predominantly oil , though in some areas something was added that wasn ’ t a protein ( e . g . egg or animal glue ). Coremans ’ s team called it “ drying oil + ‘ x ’” — possibly a natural resin .