Newly Developed Nano-Calcium Carbonate and Nano-Calcium Propanoate for the Deacidification of Library and Archival Materials

Figure 4

Raman spectra collected with excitation line λ = 785 nm. (a) Whatman paper (red line); original 18th century paper (black line) in which no signals of oxidation (marker peak at 1577 cm⁻¹) are visible. The spectra are plotted without baseline correction to evidence the increase of the fluorescence background induced by the ageing in the 18th century paper. (b) Inks on the Chartula, that is, cinnabar (red line) and iron-gall ink (black line).

(a)

(b)