Mechanistic deterioration by saponification of a 17th Century Oil Painting from the Museum of Modern Art in Cairo

Metal soap plays a role in the deformation, fading, deterioration and cracking of oil paint layers as a result of the paintings being exposured to unsuitable environmental conditions.  This leads to the interaction of metal ions with free fatty acids resulting from the hydrolysis of glycerides in the oil medium, or from protective varnish and forming metal soap, which catalyzes the hydrolysis of triglycerides in the oil medium and frees fatty acids. The decomposition of the medium then occurs and results in metal carboxylate, inside the coating film and precipitate on the surface of the painting, leading to damage. The mechanism of damage to oil paintings with lead-containin.g soap, characterized by long-chain elements of alkanes or chain soaps of lead (II), from octanoate to octadecenoate, has been analyzed using a 17^th century oil painting from the Museum of Modern Art in Cairo. The analysis used a wide range of examination and analytical methods such as FTIR, Raman Spectroscopy, SEM-EDS, XRD, Gas chromatography (GC-MS), scanning electron microscopy, stereomicroscope, and examination with polarizing microscopy after making cross-sections. This is so that targeted strategies can be developed to slow deterioration at that particular stage and help determine the state of preservation of the artworks