During these last two weeks, the CHARM team is working at the Swedish National Archives (Riksarkivet) together with experts from the Swedish National Heritage Board to study medieval manuscripts and charters using a full toolbox of scientific methods. Each technique reveals a different layer of information about how these documents were made.
We are focusing on three complementary methods:
Multispectral imaging
By photographing the documents under many wavelengths — ultraviolet, infrared, and everything in between — we can reveal hidden writing, overwritten passages, erased notes, and even earlier stages of the scribe’s work. Sometimes damage, fire, or dirt obscures the text; multispectral imaging can make it reappear.
FORS (fiber-optic reflectance spectroscopy)
FORS measures how colours reflect light across the visible and near-infrared spectrum. Even if two reds look identical to the eye, their spectral curves may reveal whether they are organic dyes, mineral pigments, or mixtures. This is crucial for understanding the palette available to medieval scribes and how it changed over time.
XRF (X-ray Fluorescence) with the Bruker CRONO
We are using a mobile micro-XRF scanner designed for non-contact, non-destructive analysis, ideal for delicate heritage materials. It can scan large areas (up to 600 × 450 mm) and detect a wide range of elements (from Mg to U) without any sampling. The result: precise clues about what materials were used. For example, iron in inks, lead in pigments, or mercury in vermilion.
We are grateful to our Swedish colleagues for their collaboration and look forward to sharing the discoveries that emerge from this multidisciplinary work!