Acrylic colors for peace: Non-invasive study of an outdoor mural painting

In 1952, contemporary artist Federico Silva (Mexico City, 1923–2022) carried out the first outdoor mural painting: The technique at the service of peace. At the end of 2021, the project for the study and conservation of this mural began with a diagnosis of its conservation, which was done through a multi-technique study based on the experience acquired in research projects from other contemporary mural paintings. This included the proposal of an adequate conservation strategy to resolve the stability of the painting, since the behavior of the synthetic paints exposed to the different effects of the outdoor environment has altered the perception, form and meaning of the mural. Main results from this approach by documentation and global examination with Visible Imaging and Digital Microscopy, allowed us to describe the color palette and its alterations. Additional examination of cross sections acquired from this mural, allowed a material characterization by means of optical microscopy (OM), micro-hyperspectral imaging, Fourier transformed infrared spectroscopy and X-ray fluorescence spectroscopies.