In the field of preservation the opinion has been spreading that is necessary to promote more and more contact between humanistic and scientific sectors. After all, this kind of intervention concerns the study of materials and, therefore, it requires a rich store of knowledge that must get rid of the "trade secrets" empirism, which is typical inside the handicraft environment. An example of benefit resulting from synergy between humanistic and scientific fields is given by the intervention in the restoration and rediscovery of the loft frescoes in the Cathedral of Aosta, which belong to the Ottonian period (XI century). The planning of recovery intervention has required scientific understanding which was able to fill the gaps in our knowledge, regarding both historical-artistic and preservation interests. Analytical applications have availed themselves of various technologies aimed at the characterisation of the materials. The study has been led with the help of X-ray diffraction, ion chromatography, infrared spectrophotometry and optical microscopy. The use of histochemical and immunological techniques has enabled the quantitative characterisation of binding materials/alloying elements.