Capturing Watermarks
The completed watermark setup.
Once we had our station set up, we began to experiment with the best ways to bring out the watermarks while keeping the letter legible. Our first method was to further diffuse the light by putting a sheet of permalife paper between the plexiglass and the letters.
An example watermark shot on permalife.
The permalife made it more difficult to see the watermarks, so we abandoned that approach quickly. We had much better luck varying the shutter speed. By either speeding up or slowing down the shutter speed, depending on how the density or thickness of the paper filtered the light, we were able to get much cleaner captures than we were with the permalife.
A watermark captured with a higher shutter speed.
Finally, we opted to add some post processing as well without fully losing the appearance of the item under normal lighting conditions.. We made use of a subtle luma curve in the highlights, bringing out the watermarks without losing legibility of the letters.
A watermark that has been post-processed for clarity.
An example of a luma curve used to highlight watermarks.
All of the watermarks shot in this project, as well as the text of the letters they were taken from, are available in the University of Illinois Digital Library William Allingham Papers.
Acknowledgements
This exhibit would not have been possible without the kind support of our Rare Books and Manuscripts Library. We would like to especially thank Ana Rodrigeuz for coordinating the digitization of this collection, and Emma Wise for the excellent metadata that made sure we captured the correct watermarks.
We would also like to thank our Metadata Librarian Stephanie Luke for ensuring these items are in, and more importantly findable, in the Digital Library.
