The Winter Room that was finished by May 1615, was not the one we see today. In the brickwork behind the panelling one can see that the door to the Studiolo in the tower was moved one foot further north. The original door opening, behind the panelling, has a grey painted frame and its existence confirms that the Winter Room had two periods of decoration. So, in 1616 Christian IV decided to have the interior completely decorated with panel paintings, for which careful directives must have been given. Among these was the order for 75 paintings in Antwerp, 57 horizontal ones and 18 vertical ones. The vertical emblematic paintings in the window openings were, however, probably preserved from the first interior decoration of the room. The paintings were produced in Antwerp standard formats, including double frames for insertion in the oak wainscoting. The many registered, identical plane marks on panels and frames bear witness to quick and simultaneous work. Presumably, the few paintings without a maker's mark, as well as the painting dated 1613, had been in the stock of the art dealer or panel maker in Antwerp who received the commission.
In November 1617 the carpenters' craft, of which Michael Claessens was the dean, decided that all panel and frame makers were to put their personal mark on their work. A month later, this decision was sanctioned by the Guild of St Luke. Out of the 75 Antwerp panel paintings and frames investigated, 46 have such marks, and 57 have the original double frames. The decision of the carpenters' craft was clearly put into practice as intended. In order to honour the huge order from Christian IV, the panel maker in charge (Guilliam Aertssen?) probably took what he had in stock, besides commissioning various painters to produce a given number of paintings as quickly as possible. Perhaps he himself supplied the panels, and on receipt of the paintings, he provided them with his own prefabricated frames. In fact, many of the paintings show marks at the edges, showing that the paint was not completely dry at the time the pictures were framed. This, too, is indicative of the speed with which the Antwerp carpenters and painters worked to produce decorative material, even for noble patrons abroad. Additionally, we have recorded that 33 panels have numbers written in red chalk on the reverse, ranging from number two through 71. The numbers do not correspond to their placement in the wainscoting, and must thus relate to the manufacture of the ensemble in Antwerp. The proof of this is found in the fact that also the frames have been inscribed with corresponding numbers, pointing to a working procedure facilitating the reassembling of panels returning from the painters’ workshops with their corresponding frame before being exported.
Upon the arrival of the 75 paintings in Copenhagen, it was apparently necessary to alter the oak panelling of the walls. This part of the work was executed with such haste that the transformed parts were not given the same surface finish as that of the already existing parts. The work was carried out in the period between 1618 and 1620. In the latter year, a Danish joiner, Hans Jørgen Dill, received his payment for the final stages of the work on 'the large panel works' in the King's palatial country house outside Copenhagen, as was revealed by Bering Lissberg in 1914.1 And Gerson hit the nail on its head when he claimed that the Flemish paintings ‘were apparently rendered on commission and made to measure as a group in Antwerp at the beginning of the 17th century to serve as decoration for the walls here’.
1 Bering Liisberg 1914; see § 5.3.