Together with our cooperation partners from the National and University Library of Iceland and our external contractor from the Fraunhofer Institute for Factory Operation and Automation in Magdeburg, we are capturing watermarks in 17th-century Icelandic paper manuscripts.
We use hyperspectral scanning, a method where iron gall ink does not interfere with the depiction of watermarks. Iron gall ink is visible only in spectres up till ca. 1,200nm. The camera that we are using captures spectres between c. 1,000 and 2,500nm, ie ink is visible only in the lower spectres but not in the higher spectres.
The camera is placed on a desk with adjustable height, and a translation stage moves the manuscripts past the camera. The manuscript leaves are placed in a u-shaped frame made of blotter (acid free, archival quality) on a bookbinding station, which is fixed onto the translation stage. We secure the manuscripts leaves and the frame with various tools used in manuscript conservation, such as snake weights, to ensure both the safety of the manuscripts and the quality of the images. Our conservator has created a great setup for a smooth and efficient scanning process.
As you can see in this short video of a test scan, we are using both high tech and low tech. Stay tuned for proper images and results of the hyperspectral scanning!