Chemistry of modern paint media: The strained and collapsed painting by Alexis Harding

The paint media used by contemporary artists include a wide range of formulation of industrially produced paints based on synthetic resins and natural oils. We investigated the paint media used by the British artist Alexis Harding (born in 1973) in the painting “Quartet” (2003). The artwork exemplifies the artist's technique of mixing different paint media to obtain a sliding movement of the paint over the support, raising severe conservation issues and causing long-term instability of the paint. As a basis to develop a conservation strategy for the artwork, we investigated the composition of the paint by in situ non-invasive contactless external reflection infrared spectroscopy (ER-FTIR). The combination with laboratory analytical techniques applied on micro-samples allowed the identification of the pigments and the binders. The multi-analytical approach involved micro infrared spectroscopy (µFTIR), Raman spectroscopy, X-ray fluorescence (XRF), and mass spectrometric techniques coupled to chromatography (GC/MS and HPLC-ESI-Q-ToF) and analytical pyrolysis (Py-GC/MS and EGA-MS). The results of these micro-destructive investigations showed that the causes of the gliding of the paint are due the incompatibility between different materials superimposed by the artist: a fast drying alkyd paint and a mixture of siccative and non-siccative drying oils.