Which elements are useful for understanding the composition of ancient papyrus inks?

X-ray fluorescence spectrometry was used in mapping and spot analysis modes, to help identify which elements are useful for understanding the composition of ancient papyrus inks, for 25 papyri from four age groups. We report seven elements (Al, Si, P, S, Ca, Ti, Fe) which provide sufficient contrast to be useful for mapping analysis, and 16 elements (P, S, Cl, K, Ca, V, Mn, Ni, Cu, Zn, Rb, Sr, Nb, Ag, Ba, and Pb) which show significant differences through time. Only one element – Pb – showed sufficient contrast in the thin ink layer to be significantly different when measured on the ink and adjacent papyrus. There is greater complexity in the elemental compositions of the papyrus and ink than can be understood with a study this size and additional work is required to develop and explain the patterns observed here.