For archaeologists studying the ancient Near East, ostraca—potsherds on which notes and letters were written in ink—provide a crucial source of information. While ostraca are far more durable than papyrus, scholars have long been aware that the ink on clay can fade easily. A group of applied mathematicians, physicists, and archaeologists at Tel Aviv University have devised a form of multispectral imaging that can detect such faded writing. And unlike similar techniques already in use, this one does not require advanced or expensive equipment. Amanda Borschel-Dan writes:
A corpus of 91 ostraca written on the eve of the kingdom of Judah’s destruction by Nebuchadnezzar in 586 BCE was unearthed at Tel Arad, west of the Dead Sea, in the 1960s. . . . Containing lists of supplies and orders from military quartermasters, the shards were of immeasurable value to the study of the Hebrew language and the sociology and economy of the time period.
Now, though, with the discovery of previously invisible words and even sentences on the “blank” reverse side of one of the first shards to be examined with the new technology, the pieces have become still more important. . . . [M]any shards previously thought of as blank have been summarily disposed of at digs or during artifact recording. . . .
[The decoded ostracon] is a letter sent to Elyashiv, [thought to be the quartermaster of a military fortress], from one Ḥananyahu—the team speculates he was a quartermaster in Beersheba—and discusses the transfer of silver. [The] newly discovered text shows that Ḥananyahu also asked for wine.