In a previous post, I discussed a recent book printed in an ink which could only be seen in ultraviolet light. Sometimes it’s easy to forget that many of the books printed in the hand press period also have “hidden artwork” that we can view in normal spectrum light. I’m referring to watermarks – designs, including words, dates, and images, that are created during the papermaking process.
Handmade paper in Europe was made on rectangular wooden molds (or, British spelling, moulds) covered with fine wire. For all the details, I recommend the excellent site European Papermaking Techniques 1300-1800 by Timothy Barrett at the University of Iowa Center for the Book. Additionally, here is a video, made in 1976 at Hayle Mill in England that shows the steps of making paper by hand. The Green family produced paper this way at Hayle Mill from 1813 until 1987. Pay particular attention to the sheets being formed on the molds by the vatman, and removed from them by the coucher (pronounced “coocher”), beginning at the 3:15 mark. Watermarks are explained at 4:30 and again at the 6 minute mark.
While attending a recent class at Rare Book School at the University of Virginia, I had a chance to examine a teaching model of a paper mold, created by Timothy Moore:
In the detail below, if you look along the tops of the wooden ribs, you’ll see wire wrapped around each laid wire, securing the surface to the frame. These stand proud of the main surface, causing the paper fibers to be slightly thinner at those points, and creating the lighter “chain lines” you can see in many of the examples below. The section with straight wires in the lower left corner of the picture creates “laid” paper, while the mesh in the upper right (that looks like window screen) is used to make “wove” paper. Because the mesh covers the chain lines, they are invisible in wove paper. This was a later development, invented in the 1750s, but not in common use until the 1780s.
The Rare Book School version of the mold includes their lion logo added as a watermark:
Of course, with that big hole in the middle, the teaching mold can’t actually be used to make paper, but a similar one made this sheet, in which you can see the chain lines running vertically, as well as the lion watermark:
Watermarks are relatively easy to see in person, but can be difficult to reproduce, especially when covered by printed text. Early studies of watermarks such as those by Briquet (1923) and Churchill (1935) used a method of tracing, which is not always accurate, and can potentially damage the original. A method utilizing beta-radiography was developed in the 1950s, but it is costly in both time and materials. In the 1970s Thomas Gravell developed the “DYLUX method” for reproduction of watermarks, utilizing a special light-sensitive paper developed by Du Pont.
Digital photography, using appropriate backlighting, will probably become more prevalent in the future. I’ll close with a couple of examples from our collections, which I captured with the decidedly low-tech aid of a swing-arm lamp and an extra pair of hands. I also (very unscientifically) boosted the contrast and lowered the brightness using Photoshop. This made the colors very inaccurate, but increased the visibility of the watermarks. (Click on images for larger versions)