Yet a team of historians and scientists have still read it—thanks to high-resolution imaging and a “virtual unfolding” algorithm. Dambrogio had noticed minuscule, apparently intentional cuts and creases in a number of historical documents and eventually guessed their purpose. undergraduate student and a co-author of the paper, wrote code for an algorithm to “open” it—while keeping it locked. But the algorithm also showed exactly how the letter had been folded 300 years ago. “We have a whole big box full of what a letter looks like when it has been sealed but not opened.