A new project on the Swedish island of Gotland is using photogrammetry to record hundreds of runic inscriptions carved into the plaster walls of medieval churches—creating detailed 3D models that researchers can study long after the fragile surfaces have begun to deteriorate.
The work is being carried out by a team from Gotland Museum and the Swedish National Heritage Board. At Närs Church in southeast Gotland, researchers photographed wall sections under carefully angled lighting to capture extremely thin carvings cut into lime plaster—some visible on the surface, others surviving beneath later layers of plaster.
“They are carved very thinly in the preserved plaster of medieval churches,” says Laila Kitzler Åhfeldt, a runologist at the National Heritage Board. “Sometimes they are over-plastered, but are still present in an older layer underneath. Gotland has more of these than the rest of Sweden combined.”
Dating from the 12th to 16th centuries
Documentation of plaster inscriptions at Närs church, Gotland. Wilda Swedborg and Mike Fergusson. Photo: Emil Schön ( CC BY-NC-ND )
The inscriptions date from the 12th century through the late 16th century. While some are simple name carvings, others record practical matters connected to local communities—such as which farmers contributed to a church—or reflect disputes and claims, including “who has the right to travel over the land.”
Devotional texts also appear frequently. “Very often these are prayers such as Ave Maria or Pater noster written down in Latin or Old German,” Åhfeldt adds.
Building on earlier records—and finding more
Many plaster inscriptions in medieval churches were documented as early as the 19th century, but many are still undiscovered. Photo: Emil Schön ( CC BY-NC-ND )
Many of Gotland’s plaster inscriptions have been known for generations. In the 19th century, Per Arvid Säve travelled across the island recording runic inscriptions, and his drawings still help guide modern investigations. Researchers say some inscriptions remain intact but were later hidden behind church furnishings, while others have been lost. New finds are also common, particularly near places where inscriptions were previously recorded.
Photogrammetry allows researchers to reconstruct the plaster surface in 3D from many overlapping photographs. That is important because the inscriptions can be so shallow that they are difficult to interpret in ordinary light. With a 3D model, scholars can adjust the lighting digitally—highlighting grooves, strokes, and tool marks—to determine more confidently what was carved.
In the field, this requires careful coordination. When an inscription is located, lighting is positioned to bring out the faint lines, and a specialised camera setup captures the images needed for 3D reconstruction. Back at the computer, researchers can “turn and twist the light” to examine the carving from multiple angles.
Urgency tied to moisture
After the 3D processing, the runes appear much clearer for research. Please note that it is not the same section of the wall in the two images. Photo: Emil Schön ( CC BY-NC-ND )
The Gotland projectis funded by the Swedish National Antiquities Board and includes the participation of 3D specialist Mike Fergusson (Filo Factum AB), working alongside staff from Gotland Museum and the National Heritage Board. The initiative grew out of earlier collaboration between the Swedish National Antiquities Board and the University of Gothenburg on documenting thousands of inscriptions in St. Sophia Cathedral in Kyiv.
“Inscriptions in the Gotland churches are a parallel to the centuries-old inscriptions in the Sofia Cathedral,” Åhfeldt explains. “Many are contemporary and many times the purposes have been similar. The Norwegian stave churches also have many runic inscriptions that have been documented.”
Researchers say the work is time-sensitive because plaster is vulnerable—especially in damper conditions. With climate change linked to increased moisture in many churches, the plaster can age more quickly, making faint carvings harder to read and more likely to be lost.
“Now we simply want to back them up for posterity,” says Åhfeldt. “There are several hundred known runic inscriptions on Gotland and we are finding more. It is almost enough to go and shine a flashlight on the walls and they will appear.”
Top Image: Michael Fergusson photographs plaster inscriptions in Närs Church on Gotland. In a research project at the National Heritage Board, the runic inscriptions will be 3D digitized. Photo: Emil Schön ( CC BY-NC-ND )
A new project on the Swedish island of Gotland is using photogrammetry to record hundreds of runic inscriptions carved into the plaster walls of medieval churches—creating detailed 3D models that researchers can study long after the fragile surfaces have begun to deteriorate.
The work is being carried out by a team from Gotland Museum and the Swedish National Heritage Board. At Närs Church in southeast Gotland, researchers photographed wall sections under carefully angled lighting to capture extremely thin carvings cut into lime plaster—some visible on the surface, others surviving beneath later layers of plaster.
“They are carved very thinly in the preserved plaster of medieval churches,” says Laila Kitzler Åhfeldt, a runologist at the National Heritage Board. “Sometimes they are over-plastered, but are still present in an older layer underneath. Gotland has more of these than the rest of Sweden combined.”
Dating from the 12th to 16th centuries
The inscriptions date from the 12th century through the late 16th century. While some are simple name carvings, others record practical matters connected to local communities—such as which farmers contributed to a church—or reflect disputes and claims, including “who has the right to travel over the land.”
Devotional texts also appear frequently. “Very often these are prayers such as Ave Maria or Pater noster written down in Latin or Old German,” Åhfeldt adds.
Building on earlier records—and finding more
Many of Gotland’s plaster inscriptions have been known for generations. In the 19th century, Per Arvid Säve travelled across the island recording runic inscriptions, and his drawings still help guide modern investigations. Researchers say some inscriptions remain intact but were later hidden behind church furnishings, while others have been lost. New finds are also common, particularly near places where inscriptions were previously recorded.
Photogrammetry allows researchers to reconstruct the plaster surface in 3D from many overlapping photographs. That is important because the inscriptions can be so shallow that they are difficult to interpret in ordinary light. With a 3D model, scholars can adjust the lighting digitally—highlighting grooves, strokes, and tool marks—to determine more confidently what was carved.
In the field, this requires careful coordination. When an inscription is located, lighting is positioned to bring out the faint lines, and a specialised camera setup captures the images needed for 3D reconstruction. Back at the computer, researchers can “turn and twist the light” to examine the carving from multiple angles.
Urgency tied to moisture
The Gotland projectis funded by the Swedish National Antiquities Board and includes the participation of 3D specialist Mike Fergusson (Filo Factum AB), working alongside staff from Gotland Museum and the National Heritage Board. The initiative grew out of earlier collaboration between the Swedish National Antiquities Board and the University of Gothenburg on documenting thousands of inscriptions in St. Sophia Cathedral in Kyiv.
“Inscriptions in the Gotland churches are a parallel to the centuries-old inscriptions in the Sofia Cathedral,” Åhfeldt explains. “Many are contemporary and many times the purposes have been similar. The Norwegian stave churches also have many runic inscriptions that have been documented.”
Researchers say the work is time-sensitive because plaster is vulnerable—especially in damper conditions. With climate change linked to increased moisture in many churches, the plaster can age more quickly, making faint carvings harder to read and more likely to be lost.
“Now we simply want to back them up for posterity,” says Åhfeldt. “There are several hundred known runic inscriptions on Gotland and we are finding more. It is almost enough to go and shine a flashlight on the walls and they will appear.”
Click here to learn more about runes and inscriptions in churches from the Swedish National Heritage Board
Top Image: Michael Fergusson photographs plaster inscriptions in Närs Church on Gotland. In a research project at the National Heritage Board, the runic inscriptions will be 3D digitized. Photo: Emil Schön ( CC BY-NC-ND )
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