Heat Maps of a Torah Scroll

As ritual objects, Torah scrolls had to be written in accordance with exacting standards that evolved over time. This requirement led to successive stages of modifications, sometimes over centuries.

Sometimes alterations of the writing were done with seemingly indistinguishable writing inks. With the help of µXRF scanning of selected sheets from Rhineland 1217, a Torah scroll from a private Hungarian collection, various corrections done in very similar inks could be identified and visualised by displaying the results of the scans as heatmaps. The approach is based on displaying the intensity of elemental distributions as heat maps that represent data recorded with a scanning µX-ray fluorescence spectrometer. The heat maps present the data so as to facilitate digitally identifying and distinguishing between inks used to produce, correct, and reink the medieval Torah scroll.

The solid material analysis evidence and its presentation as heat maps made it possible to discriminate between original and altered portions of text that in some cases would have been impossible.