paper

Evidence

"certain manuscripts, all written on paper, present a high inhomogeneity of metallic components in their support. ... An example will be given with manuscript T-S 10J15.16 (Figure 4.29a). ... the inhomogeneity of the elements from the support make the establishment of a fingerprint impossible (Figure 4.29c)."

Remarks

In manuscripts like T-S 10J15.16, the paper support contains significant but highly irregular concentrations of iron and calcium. For iron (Fe), most data points spread from 15x10^6 to 40x10^6 raw counts, making it impossible to differentiate ink components from support components (p. 122).