Evaluation of the effect of cleaning on the morphological properties of ancient paper surface

In the conservation field, the original mor- phology and texture of the paper surface represent an important aspect to be preserved as historical evidence of the papermaking process. The aim of this preliminary research is to evaluate the effects of aqueous (cellulose ethers, rigid gels of Agar and Gellan gum) and not aqueous cleaning treatments (a typical dry cleaning treatment with wishab sponge) on the original surface morphology of late nineteenth century paper. Nine- teenth century newspaper paper was chosen because it is strongly affected by cellulose oxidation and depolimer- ization due to the rough materials (wood pulp) and the process used at the time and to the environmental conditions (light, humidity, temperature) to which such paper has been subjected. A preliminary characterization of the paper with Herzberg and Phlor- oglucinol reactives and Fourier Transform infrared Spectroscopy analysis was performed to understand the paper composition and the type of inorganic fillers used. The paper surface microtopography was then measured by contact profilometry to analyze the effects of the cleaning treatments on paper surface roughness. The effects of the cleaning action was qualitatively evalu- ated by means of stereo microscopy and scanning electron microscopy. Preliminary results suggest that the treatments which are most respectful of the original surface micromorphology of the paper are those based on the use of rigid gels (Agar and Gellan gum), because they determine the smallest variation in the roughness of surface paper, unlike the application of cellulose ethers by brush. This finding was confirmed by statistical analysis of the roughness results by means of ANOVA and Tukey HSD post hoc test.