Scientific investigation of five related portraits in the Stirling Maxwell Collection is currently under way. The results will be compared with those for the Lady in a Fur Wrap, which underwent specialised technical examination using the world-class facilities and expertise at the Museo Nacional del Prado, Madrid in 2014, as well as with those for other paintings in the Prado and elsewhere. Though there is no guarantee of definitive results, detailed comparative assessment and discussion results will certainly help us to learn more about artists’ materials and techniques in 16th-century Spain.
The technical examination led by the University of Glasgow is a collaboration involving several partners and international specialists. It includes examination of the paintings’ surface, as well as analysis of microscopic paint samples in the research laboratory of the Technical Art History Group at the University of Glasgow, using optical microscopy and fluorescent staining. X-radiography of the paintings has been carried out at the University’s School of Veterinary Medicine. With no dedicated facilities for X-raying paintings throughout Scotland, this partnership provides a welcome opportunity for the team to analyse aspects of artworks not visible to the naked eye. The X-ray process should provide information about the artist’s materials and techniques, as well as revealing more about an artist’s particular style.
Historic Environment Scotland are contributing to the research by providing specialist staff and equipment: Infrared Reflectography (IRR), which may help detect preliminary sketches or underdrawings by artists; and X-ray fluorescence (XRF), which can help to analyse the chemical elements present in the materials used to create the paintings. Additional advanced analytical techniques are being performed by other external partners. The Doerner Institut, Munich, is undertaking Gas Chromatography Mass Spectrometry (GC-MS), a procedure that is ideal for providing detailed chemical information on the organic materials found in paint samples, especially the materials used to bind them. Fourier Transform Infrared imaging (FTIR) will be carried out at Bern University of Applied Sciences in their Art Technological Laboratory.