paintings, flower paintings and still lifes of various types. The development of many of these types of painting was decisively influenced by 17th-century Dutch artists. The widely held theory of the "hierarchy of genres" in painting, whereby some types were regarded as more prestigious than others, led many painters to want to produce history painting. However, this was the hardest to sell, as even Rembrandt found. Many were forced to produce portraits or genre scenes, which sold much more easily. In descending order of status, the categories in the hierarchy were: history painting, including allegories and popular religious subjects. portrait painting, including the tronie genre painting or scenes of everyday life landscape, including seascapes, battlescenes, cityscapes, and ruins (landscapists were the "common footmen in the Army of Art" according to Samuel van Hoogstraten.) still life The Dutch concentrated heavily on the "lower" categories, but by no means rejected the concept of the hierarchy. Most paintings were relatively small – the only common type of really large paintings were group portraits. Painting directly onto walls hardly existed; when a wall-space in a public building needed decorating, fitted framed canvas was normally used. For the extra precision possible on a hard surface, many painters continued to use wooden panels, some time after the rest of Western Europe had abandoned them; some used copper plates, usually recycling plates from printmaking. In turn, the number of surviving Golden Age paintings was reduced by them being overpainted with new works by artists throughout the 18th and 19th century – poor ones were usually cheaper than a new canvas, stretcher and frame. There was very little Dutch sculpture during the period; it is mostly found in tomb monuments and attached to public buildings, and small sculptures for houses are a noticeable gap, their place taken by silverware and ceramics. Painted delftware tiles were very cheap and common, if rarely of really high quality, but silver, especially in the auricular style, led Europe. With this exception, the best artistic efforts were concentrated on painting and printmaking. The art world Foreigners remarked on the enormous quantities of art produced and the large fairs where many paintings were sold – it has been roughly estimated that over 1.3 million Dutch pictures were painted in the 20 years after 1640 alone. The volume of production meant that prices were fairly low, except for the best known artists; as in most