If that's true, and after having watched the documentary it's hard for me to believe it's not, then Vermeer was kind of like a magician : his paintings were mad

If that's true, and after having watched the documentary it's hard for me to believe it's not, then Vermeer was kind of like a magician : his paintings were made with a trick that he kept secret. On one hand the whole story is charming but on the other hand I have the feeling Vermeer was kind of a dick not to reveal this technique to the World.