Can the damaged or hidden writing be made visible again?
Revealing Lost and Hidden Writing
Samaneh Ehteram, Kyle Ann Huskin, Ivan Shevchuk
It is common for written artefacts from all regions and time periods to become damaged and illegible over the course of their lives. The damage may be intentional (e.g., palimpsesting, erasure, censorship) or unintentional (e.g., water damage, friction/wear, gelatinization, etc.). Before the twenty-first century, researchers relied on destructive methods, such as chemical reagents, or on tedious analog photographic techniques to reveal lost writing. Since the early 2000’s, digital photography has made it possible to manipulate image data, enabling the use of non-destructive techniques, such as multispectral imaging (MSI), reflectance transformation imaging (RTI), hyperspectral imaging (HSI), and infrared reflectography (IRR) to reveal writing and images. In some instances, they can also be revealed by mapping using spectroscopic techniques, such as X-ray Fluorescence (XRF) and Raman spectroscopy. The latter is particularly relevant to identify erased or damaged inscriptions on marble headstones. Similarly, traces of colour detected with X-Ray fluorescence or Raman spectroscopy could be used as a marker of the exact location of inscriptions.
Additionally, writing can be hidden to the sight by encasing the WA in a sealed container, by the application of additional writing supports on the writing or due to phenomena resulting in an adhesion of the original components of a WA. The process of hiding writing may be intentional, as in the case of letters or the application of additional layers of writing support that serve reworking on drafts, corrections, updatings and censorship. In other cases, the hiding might be unintentional: due to the conservation conditions, for example the carbonised scrolls (Herculaneum papyri, en-Gedi parchment scroll) that cannot be unrolled, or as a consequence of repurposing of the material, for instance recycling pages or pieces of manuscripts as lining, pasteboard and other components of a binding. In these cases, techniques such as X-ray Computed Tomography (X-ray CT), and Infrared Reflectography can be used to reveal the hidden writings.