That is one of the findings of eight years of analysis of van Gogh’s palette, pigments, letters, notebooks and canvases by scientists at Shell, the oil company, in collaboration with the Dutch Cultural Heritage Agency and curators at the Van Gogh Museum here, which owns the world’s largest collection of works by the Dutch post-impressionist.
The results of that study will be revealed in an exhibition “Van Gogh at Work,” which opens May 1 and features about 200 paintings and drawings, 150 of them by van Gogh and others by contemporaries including Paul Gauguin and Émile Bernard.
“Van Gogh at Work,” which will inhabit all four floors of the museum’s gallery space until Jan. 12, goes on view as the museum reopens after a seven-month renovation that cost €21 million, or about $27.5 million.
Article source: http://www.nytimes.com/2013/04/30/arts/30iht-vangogh30.html?pagewanted=all