The importance of performing physico-chemical analyzes in the study of old wall decorations is well established. Much has already been said about the contributions of archaeometry to the identification of pigments and the characterization of preparation mortars, but we lack a more global reflection, on the territorial and diachronic scale, concerning the techniques of ancient wall painting. This volume, which collects the proceedings of the eponymous conference held in Louvain-la-Neuve (Belgium) on April 21, 2017, aims to compare various local realities of Roman Italy (Rome, Ostia, Pompeii, Herculaneum, Aquileia, Cottanello) and provinces (Gaul, Betic, Pannonia, Asia Minor), using the “technical approach” to answer certain questions: are there constants or transformations in the technique of execution of the wall paintings over time ? Are there specific characteristics of a particular area or period? How did the painters of Antiquity work?