Although Joshua Reynolds (1723-92) is lauded as one of Britain’s greatest portraitists, there is one group that is less enthusiastic about his substantial body of work: conservators. The artist’s eagerness to experiment with new techniques and materials, some of which have proved to be unstable, means that his works are often challenging to treat. There is a long history of uneasiness about restoring them: it is said that his contemporary Thomas Lawrence warned a man who had just bought a work by Reynolds at auction not to have it restored.
In 2009, the Wallace Collection in London used its 12 paintings by Reynolds as a springboard for a larger project. With funding from the Paul Mellon Centre for Studies in British Art, the institution collaborated with London’s National Gallery and the Yale Center for British Art, Connecticut, to conduct a technical investigation of the artist’s materials and methods. The results of the Reynolds Research Project form a show that opens at the Wallace Collection this month.
Tricky to treat
Reynolds’s experimental nature means that there is no one-size-fits-all approach to treating his works. “If you look at one Reynolds, there is no guarantee that the next will be the same,” says Alexandra Gent, the project’s lead paintings conservator. “There is always this concern that you may have one at the bad end of the spectrum and so the tools you would normally use might not work.” Reynolds did not share his methods; his surviving “technical notes” constitute a few notes scribbled in his ledgers.
The artist was a great fan of the Old Masters, admiring “the translucency and colouring in their work, qualities he tried to recreate”, Gent says. “But he was looking at old paintings that had changed in appearance over time.” Reynolds was so keen to discover how other artists achieved certain effects that he bought paintings so he could scrape back the layers. He even “restored” or “improved” some Old Masters from his art collection, including Rembrandt’s Susanna and the Elders, 1647, now in Berlin’s Gemäldegalerie, and Prince Baltasar Carlos in Black and Silver, around 1640, which is attributed to the School of Velázquez and is now in the Wallace Collection.
One of the tricks Reynolds used to achieve the translucent appearance of aged paint was to add varnish to his oil paint. This also made the paint touch-dry—an added bonus for an artist who built up rich surfaces by using layer upon layer of paint, often with layers of varnish in between. But adding varnish to paint can cause it to crack. An examination of Reynolds’s portrait of the courtesan Nelly O’Brien, around 1762, showed that the colours of the foliage were toned down with thin layers of brownish glaze.
The flesh tones of many of the artist’s early portraits, including The 4th Duke of Queensberry as Earl of March, 1759, have faded because of his choice of pigments: the red-lake pigment he mixed with white is light-sensitive. He used bitumen, which never fully dries when mixed with oil, potentially creating cracks on the work’s surface, and the modified oil paint megilp, which “has a rich, buttery consistency, but self-destructs because of the varnish in it”, Gent says.
The National Gallery’s next Technical Bulletin will include research from the Reynolds Research Project.
• Joshua Reynolds: Experiments in Paint, Wallace Collection, London, 12 March-7 June
Originally appeared in The Art Newspaper as 'Why Reynolds’s paintings can auto-destruct'