Leiden University wrote that the team was able to scan iron particles in the ink on the letter using an X-ray scanner. Then the scanned characters were run through an algorithm.
Special folding techniques
It took the university four years to develop that algorithm, with help from the Massachusetts Institute of Technology (MIT), one of the leading universities in technology in the United States. With this technique, the team was able to create a 3D representation of the entire letter, including how to fold it.
At that time, the crafts were folded together using a special folding technology. “The method the team devised allows them to read the content while keeping the unique folding method of the historical document completely intact,” said associate professor Nadine Ackerman in a statement from Leiden University.
In the letter, Jacques Senac asks his cousin Pierre Le Perse an obituary. Le Pers was a dealer in The Hague at the time. The message has not been read before.
With the new method, researchers are now able to read more characters without harming physical objects. They are currently looking for a collection of six hundred unopened messages in the possession of The Hague Sound and Vision.
The letters come from the group of postal worker, Simone de Brienne. At that time, the recipient of the letter had to pay for the message, but some recipients were not found or did not want to pay the money. So Breen saved it in his archive, which contains a total of 2,600 characters. Most of it is open.