Historians can use scanning to peek inside mummies without risking damage, but that hasn't been true for the papyrus boxes those mummies were placed in before entering the tomb. If you've wanted to read the discarded everyday writing on that papyrus, you've typically had to destroy the boxes. That won't be necessary from now on, though: researchers at University College London have developed a scanning technique that lets you read a mummy case's writing while leaving it intact.
If you scan the cases with light at different frequencies, you can make the ink glow and thus see under the paste and plaster that would normally obscure the text. A lot of the writing is unspectacular (the BBC describes them as shopping lists and tax returns), but that's the point -- it's about discovering Egyptian history beyond royalty and other famous people.
The technique has already found success with one mummy stored in Kent. It's not certain that it'll find widespread adoption, but it's hard to see historians turning this down. Much as with techniques used to read closed books, this lets researchers have the best of both worlds: they can read 'secret' text without having to sacrifice priceless relics.