intent on realism. Rembrandt evolved a more effective way of painting patterned lace, laying in broad white stokes, and then painting lightly in black to show the pattern. Another way of doing this was to paint in white over a black layer, and scratch off the white with the end of the brush to show the pattern. At the end of the century there was a fashion for showing sitters in a semi-fancy dress, begun in England by van Dyck in the 1630s, known as "picturesque" or "Roman" dress. Aristocratic, and militia, sitters allowed themselves more freedom in bright dress and expansive settings than burghers, and religious affiliations probably affected many depictions. By the end of the century aristocratic, or French, values were spreading among the burghers, and depictions were allowed more freedom and display. A distinctive type of painting, combining elements of the portrait, history, and genre painting was the tronie. This was usually a half-length of a single figure which concentrated on capturing an unusual mood or expression. The actual identity of the model was not supposed to be important, but they might represent a historical figure and be in exotic or historic costume. Jan Lievens and Rembrandt, many of whose self-portraits are also tronies (especially his etched ones), were among those who developed the genre. Family portraits tended, as in Flanders, to be set outdoors in gardens, but without an extensive view as later in England, and to be relatively informal in dress and mood. Group portraits, largely a Dutch invention, were popular among the large numbers of civic associations that were a notable part of Dutch life, such as the officers of a city's schutterij or militia guards, boards of trustees and regents of guilds and charitable foundations and the like. Especially in the first half of the century, portraits were very formal and stiff in composition. Groups were often seated around a table, each person looking at the viewer. Much attention was paid to fine details in clothing, and where applicable, to furniture and other signs of a person's position in society. Later in the century groups became livelier and colours brighter. Rembrandt's Syndics of the Drapers' Guild is a subtle treatment of a group round a table. Scientists often posed with instruments and objects of their study around them. Physicians sometimes posed together around a cadaver, a so-called 'Anatomical Lesson', the most famous one