Each of these approaches provides a set of facts about an artifact's condition, age or origins.The method of choice for any given situation is determined by several factors, including: the objectives of the investigator (authentication, preservation, personal curiosity); the relative value of the paper (historically, legally, personally); and whether the information gained from destructive testing will outweigh the loss of material samples.
(Correspondent): In these vaults, on these shelves, in these boxes at Oxford University, ancient clues—2,000 years old—to a glorious human past; wrapped in printed paper, fragments of ancient paper, pieces of the D. The stuff is really quite durable, in a way, more durable than the paper you're used to taking notes on today.
What papyrologists really needed was this—an equivalent to Superman's x-ray vision—a way to see through whatever was on the surface of papyri—ancient food stains, burn marks, mummy paint—see through to the writing underneath.
To try to read these faded, stained, or even charred bits, a NASA scientist has turned to multispectral imaging technology.
Could this be just the kind of "X-ray vision" the scholars need? And the secret password is always invisible, hidden until you slid the paper into this sleeve, and then the secret word is revealed. D., a mid-sized capital city in Greek-ruled Egypt, the city of Oxyrhynchus—actually, found buried in the Oxyrhynchus city dump, in rubbish mounds.
Additionally, entries which have been obliterated may be readable using these methods, for example by rendering the obliterating ink transparent under a particular light source.