New paper: The Palette of the Medieval North

A key study, paving the way for the investigations of CHARM, is just hot off the press!  (Winther et al. 2025, with Tuomas Heikkilä from CHARM as one of the authors) published in npj Heritage Science, studied the vibrant colors of medieval Swedish manuscripts. By analyzing ten parchment fragments from the 12th to 15th centuries, the team uncovered a fascinating mix of traditional and rare materials. These manuscripts, once used in everyday church life across medieval Sweden and Finland, offer a glimpse into historical book-making practices and artistic choices.

Using non-invasive scientific techniques, the study identified a variety of reds, blues, greens, and yellows, showing how pigments were sourced through trade and learned networks across Europe. The findings also hint at collaboration among different artisans, as the materials and techniques varied even within the same document. Beyond uncovering medieval colors, the research highlights how science can help piece together the history of fragmented manuscripts, deepening our understanding of Nordic book culture.

Methods and results in a nutshell:

• Microscopy for close examination of pigment application
• Hyperspectral imaging in visible and ultraviolet light to detect colour variations
• X-ray fluorescence spectrometry (XRF) to determine elemental composition
• Reflectance spectroscopy in UV, visible, and infrared ranges to analyze pigment signatures
• Raman spectroscopy for molecular identification of pigments and inks

Pigments and inks:

• Reds: Vermilion, red lead, and an unusual iron-based red with copper particles
• Blues: Azurite and ultramarine which was used in a 12th-century calendar
• Greens: Copper-based greens and green earth (iron-based)
• Yellows: Orpiment
• Inks: A probable tannin-based ink without iron or carbon