In the latest Woody Allen movie Midnight in Paris the protagonist, played by Owen Wilson, is writing a book on nostalgia. Similarly, the man I was with in Paris’s Tuileries gardens some days ago was also most definitely trafficking in nostalgia. Charmingly scruffy and with fingers still encrusted with remnants of his work, he is a restorer I met during his lunch break. He was working on the conservation of a 17th c. Venetian ceiling in the Louvre – complete with gilded plaster, frescoed putti, and all the splendor of a bygone era.
Halfway through our lunch he went rummaging into his well-worn leather sack, a mischievous grin on his lips. To my delight, he extracted a bag full of five or six small and oddly shaped bottles containing amber colored, resinous liquids at various stages of solidification. My eyes went quickly scanning for those oh-so familiar elements… the pungent smell of solvent, the encrusted caps…all signs confirming that the content was old!
Siccatif de Harlem, the resinous liquid in those bottles,is an artist’s material based on hard copal varnishes. Secreted by the trees of Trachylobium species in Africa, Hymenaea courbaril in South America, and Agathis australis in New Zealand, copals are also obtained as fossil resins from Zaire and Zanzibar. This hard resin cannot simply be diluted in oil or thinned with solvents; it needs to be boiled for a long time and thus melted at high temperature. When mixed with traditional fine artist’s oil paint from a tube this material can accelerate its drying (from several months to a few days!) and dramatically alters the paint’s look and flow. Research conservators here at the Art Institute recently put on the sorcerer’s hat and made replicas of what results an artist may obtain in his studio with this siccatif: see for yourself how the viscous consistency of oil paint is transformed into a glossy, flat, almost enamel-like surface.
Here's an image of the typical, viscous consistency of oil paint from an artist’s tube:
And here's an image from the same tube of paint, but after the addition of Siccatif de Harlem:
In many ways science is like love: sometimes it is hard to find a match if you don’t know what you are looking for. And the siccatif you can buy today has often nothing more in common with the original turn of the century product than a name on its label, just like those photos people post on dating websites, picturing a 10-year younger version of themselves.
But now, with these bottles of Siccatif de Harlem in my suitcase I felt like a true art-detective, collecting fingerprints of likely candidates to compare with my mystery paints. The unknown paint is a minuscule fragment of a painting from the Art Institute of Chicago’s Still Life, 1922, by Pablo Picasso, nearly invisible to the naked eye. Painstakingly going through the online archives of the Picasso Museum in Paris we found another clue—a receipt proving that Picasso did indeed buy Siccatif de Harlem.
I can feel the excitement as the pieces of the puzzle are coming together. And so the quest begins. After unpacking my suitcase I’ll analyze the resinous material from the small bottles. Keep your fingers crossed that it is a match.
—Francesca C., Andrew W. Mellon Senior Conservation Scientist