Two Portraits of Christian, Prince-Elect of Denmark, attributed to Pieter Isaacsz examined

The painting technique of two portraits presumably from the 17th century owned by the Museum of National History at Frederiksborg Castle were analysed at CATS – The Centre for Art Technological Studies and Conservation - at Statens Museum for Kunst with the purpose of clarifying whether both portraits could be concurrent and painted by Pieter Isaacsz (1569-1625). The paintings are executed in oil on canvas and depict Christian, Prince-Elect of Denmark (1603-1647). A pre-study by X-radiography, infrared reflectograhy and paint cross-section was carried out in CATS in 2012, in order to examine the canvas-support, possible underdrawings and the stratigraphy of the paint-layers. The results of the pre-study were compiled in a report (attached as Appendix 1). Based on the pre-study it was decided to carry out further cientific
analyses. These complementary and in-depth analyses were carried out in 2014 by Dr. Anna Vila and Dr. David Buti. The analyses involved chemical characterization of the elemental compositions in specific areas of the two paintings by SEM-EDX (scanning electron microscopy with energy dispersive X-ray spectroscopy), Raman spectroscopy and FTIR (Fourier transform infrared spectroscopy). The analyses were focused on a comparison between the ground layers, the red paint layers in the garments, and the background draperies painted in green and blue, respectively.