Gauguin had so admired van Gogh's early sunflower paintings that van Gogh not only painted more versions but copied some of them.

Readers who know van Gogh's sunflower paintings will remember their thickly worked paint structure.

His commissions included large sunflower paintings for the Imperial Hotel, Torquay, and a mural for the American Chamber of Commerce in London.

By that he meant the 1987 auction of one of van Gogh's sunflower paintings, which sold for $39.9 million, then a record price for a painting.

The next week was wasted by having every child in the class make his/her own copy of Van Gogh's sunflower painting.

The blockbuster show, which originated at the Art Institute of Chicago, concentrates on the autumn of 1888, when the two volatile artists worked on sunflower paintings in Arles.

Some 150 paintings, including five sunflower paintings, will be on display in Amsterdam; about 250 drawings, especially from van Gogh's early period, will be displayed in Otterlo.

"You get calls from people who say they have a sunflower painting 'just like the one you sold,' " says Nancy Whyte, an Impressionism specialist at Christie's.

Sunflowers@vangoghgallery.com, offers an analysis of two sunflower paintings.

The sunflower paintings, some of the most recognizable of Van Gogh's paintings, were created in this time.