Ways to detect an erasure
[To see these images at higher resolution, please click on each photo]
Microscope photography makes it possible to discern even the tiniest ink and paper alterations. In photo no. 1, the stereoscopic microscope (adjusted from a 20 to a 35 times magnification) shows irregular and ruffled cellulose fibres especially under the diagonal ink line; this finding is an indication of an abrasive action probably carried out by an eraser. One can also notice with clarity the ink anomalous distribution, with micro-particles scattered outside the regular pen stroke: the eraser abrasive intervention is confirmed and there is positive identification of a correction attempt along the rising diagonal.
In photo no. 2 (taken with only ultraviolet lighting) the erasure results ascertained beyond any doubt.