This chapter reports on the usage of inorganic nanomaterials for the compatible and stable consolidation of wall paintings and stone artefacts. Traditional consolidants, either inorganic [aqueous Ca(OH)₂ solutions or dispersions] or organic [e.g. acrylate or vinyl acetate polymers], exhibit several limitations and drawbacks. On the other hand, dispersions of calcium hydroxide nanoparticles in short-chain aliphatic alcohols ensure optimal consolidation effects, as highlighted by several case studies. Mixed formulations, including barium, strontium, magnesium and calcium hydroxides, can be used on salt-contaminated plasters and other carbonate-based stones, owing to their different chemical reactivity and to the physico-chemical characteristics of the carbonates they form.