The medievalists at Medievalists.net are all excited over a new technology that “unerases” writings that were erased by scribes to make more room on precious parchment:
Using cutting-edge technology, European scientists have uncovered new fragments by Euripides and an unknown ancient commentary on Aristotle.
These writings were on parchments that were washed off and overwritten in medieval times. Using advanced multispectral imaging methods, the Palamedes project, based out of the Universities of Göttingen and Bologna were able to see the original writings in the manuscripts, one of which is located at the library of the Greek Orthodox Patriarchate in Jerusalem, while the other can be found at the National Library of France in Paris.
More about Palamedes (short for PALimpsestorum Aetatis Mediae EDitiones Et Studia) and their palimpsest discoveries over here.