Cleaning of the surface of murals on mud, at Templo Pintado (900 – 1533 AD), on the site of Pachacamac, about 30 km south of Lima, Peru. This cleaning is done in order to make a sample for analysis. These will make it possible to determine the composition of the paints in order to understand their manufacturing technique, the origin of the coloring materials used and to participate in their conservation. Since 2008, these murals are the subject of a research and conservation program led by the “Museo de Sitio de Pachacamac”, scientific partner of the IFEA (French Institute of Andean Studies). As part of this work, archeometry is a pre-eminent methodological tool for anthropological knowledge of pre-Hispanic civilizations.