The painting that Griet inspired Vermeer to paint while she is washing the window of his studio is called "Woman with a Water Jug". It is currently at the Metropolitan Museum of Art in NY.
Although Vermeer and the painting both are real historic figures, the screenplay is based on Tracy Chevalier's novel and therefore largely fictional or hypothetical. Only 36 Vermeer paintings are known to exist today, and none of the models has ever been positively identified. A poster of the painting in her bedroom inspired Chevalier to write her own version of how it came to exist, based on the framework of Vermeer's known history. Chevalier sold the film rights and opted not to have any involvement in the film or screenplay, although after its release said that she was pleased with the results.
In the movie, Vermeer is working on the painting "The Concert", which was stolen in 1990 and is still missing. It is now valued at over 200 million dollars and one of the most famous stolen painting in the world.
Out of all the animals used in the various scenes, Scarlett Johansson fell in love with one of the cats and named it 'Merkin'. The production went to great lengths to allow her to adopt the cat and arrange it to be transported from Luxembourg to New York city.
The movie was partially shot on the Venice set that had been built in Luxembourg for Secret Passage (2004). For this movie Venice was modified to become Delft.