(b Leiden, 7 Apr. 1613; bur. Leiden, 9 Feb. 1675). Dutch painter. He spent all his career in Leiden, where he became the first pupil of the young Rembrandt in 1628. His early work was closely based on his master's, but after Rembrandt moved to Amsterdam in 1631/2, Dou developed a style of his own characterized by minute detail and a surface of almost enamelled smoothness (he had initially trained in his father's profession of glass engraving and this background must have helped instil a love of glossy surfaces). He was astonishingly fastidious about his tools and working conditions, with a particular horror of dust, and sometimes painted with the aid of a magnifying glass. In about 1640 he was visited by Sandrart, who ‘praised the great care that he had lavished on painting a broomstick hardly larger than a fingernail’, only for Dou to reply that ‘he would need three more days to finish it’.