On both bills, the same person with the same pen, added the number "2" to the amounts.

We were able to solve the case by applying chromatic luminescence (non-destructive physical test), which revealed an increased evaporation of ink on the €1,000 amount compared to the "2", as it had been on the paper for longer.

The more volatile components of inks begin to evaporate from the moment of signing or writing, due to an oxidation process.