Digital Preservation Technology

Around the mid twentieth century, book historians began to use UV light to read damaged or faded manuscripts. The collagen in parchment or vellum absorbs much less UV light than the inks, causing the membrane to glow a soft blue while the inks appear black (see below for an example). This technique has allowed for the recovery of much of the erased text of Grettisfaersla, though some 52 lines remain illegible. 

There is some hope that the remaining text can be recovered through multispectral imaging. This process is essentially a sort of photography, except that it captures a much broader range of the electromagnetic spectrum than conventional methods. The photo on the left shows multispectral imaging equipment currently in use at the British Library.