in the art collection of Archduke Leopold Wilhelm. While the project was initially planned to include the entire collection of the Archduke, the Archduke returned to Vienna before the project was completed. As a result, ultimately only a series of 246 plates was produced, of which 243 depicted about half of the Italian paintings then owned by the Archduke). In the preparation of this project, Teniers first painted reduced modelli after the original works on panels of roughly 17 by 25 in dimensions. These were then engraved on the same scale by a pool of 12 engravers. Teniers used full colour in the modelli, rather than grisaille. This could mean that he intended these reproductions to function as independent records of some of these Italian paintings in the Archduke's collection. From the many modelli, which have been preserved, it is obvious that Teniers's copies constitute a true record of the originals even while he left out details and painted them in his typical fluid and transparent manner. The engraving of the catalog by engravers who worked after the modelli, not the originals, was started by 1656. In the 17th century there existed no efficient method for inverting images. As a result, most of the prints in the catalog are reverse images of the originals. Each print gives the name of the author of the original work on the left hand side (indicated by the letter 'p' for 'pinxit', Latin for 'painted by') and the engraver of the print on the right hand side (indicated by the letter 's' for 'sculpsit', Latin for 'engraved by'). Some editions also indicated the original dimensions of the paintings. Teniers's modelli and the Theatrum pictorium serve as a record for some important paintings the whereabouts of which are currently unknown. For instance, the modelli in the Metropolitan Museum of Art of the Old Age in Search of Youth attributed by Teniers to Correggio and the Adam and Eve after Padovanino are the most important records of these lost paintings. The Theatrum Pictorium had an important impact on the manner in which collections were organised, appreciated and published and continued to be used as a reference book during the 18th century. Singeries Teniers contributed to the spread of the genre of the 'monkey scene', also called 'singerie' (which in French means a 'comical grimace, behaviour or trick' and is derived from 'singe', the French word for