A non-invasive multi-technique investigation of Banqueting House Whitehall Rubens ceiling paintings

The nine ceiling paintings at the Banqueting House Whitehall, painted by Peter Paul Rubens and studio is one of the largest and most complex works by the master, and has survived in its original location for almost 400 years. Historic Royal Palaces' current Banqueting House Whitehall conservation and re-presentation project provided a rare opportunity to carry out a first-ever full and systematic technical conservation survey to determine how the paintings were created and how they have changed over the years. In 2018, scaffold access enabled the present technical survey to be conducted in-situ with a non-invasive multi-technique approach using a set of portable instruments. Notably, X-ray fluorescence (XRF) spectroscopy, integrated XRF/X-ray diffraction (XRD), optical coherence tomography (OCT) and FT-IR reflection spectroscopy were employed to study two of the paintings, the large central oval The Apotheosis of King James I (Apotheosis) and the south end rectangle The Wise Rule of King James I (Wise Rule). Results revealed information about the materials used by Rubens and his studio for the production of these large-scale paintings. Pigments identified by XRF and XRD analysis including hydrocerussite, vermillion, smalt, copper-based blue or green pigments, lead-tin yellow and iron oxide-based pigments. OCT and FT-IR analyses provided information about the nature of compounds resulting from the alteration of some original materials and the condition of varnish layers.