They are direct surveys to define the amount and the nature of layers of plaster and paint existing on the walls or on the ceilings, whether they are wooden, frescoed or simply painted.
The stratigraphic investigation is made by taking samples of about 15x15 cm on the areas in question. All mortar and paint is removed layer by layer, either manually or mechanically (with a scalpel, small hammers, etc.) and/or chemically (with inorganic salt and a de-ionised water solution) to reveal any previously existing decoration or painting dating to the period of the building’s construction. This procedure culminates n a technical report, accompanied by photographic documentation, reporting the outcomes. This is given to the Italian Department for the Supervision of Architectural Heritage for every modification or demolition to the building’s structure.