Inside the Conservation Lab: Three-Dimensional "Seal-Print"
As the New York Public Library's Paper Conservator, most of the objects that I treat flat paper items, such as documents, maps, and prints. A more unusual project came to me last year from the Prints Division collection. It is a small, 15th century German, three-dimensional print entitled Coronation of the Virgin by the Trinity.
The tableau features the Virgin Mary in the center wearing a crown surrounded by the Father, Son, and Holy Spirit. A close examination of the object under magnification shows three layers of paper. The paper is dark brown in color, although lighter at the edges. It is unclear whether this dark brown color is the result of age, dirt, soot, discolored pigment, or a coating, such as wax, varnish, or oil. Traces of red, black, and gold colorants are still evident in places. There may be other colors present that are obscured by the overall dark tone. I examined it under ultraviolet illumination (more about ultraviolet examination of museum objects), but did not detect any fluorescence that would have provided clues about the pigments or coating.
The print was featured in a 1932 article entitled Pasteprints and Sealprints in Metropolitan Museum Studies, written by T.O. Mabbott and is listed in the Handbuch der Holz- und Metallschnitte des xv. Jahrhunderts, or "Handbook of Woodcuts and Metalcuts of the Fifteenth Century," a comprehensive survey of all of the prints known to exist from that time, compiled by W. L. Schreiber in 1926. It is identified as a 'sealprint'; a term I was unfamiliar with. Professor Mabbott explains in his article that he coined the term "sealprint" because they reminded him of how a "modern notary public makes a seal, by pressing a piece of paper over a form."
Both references claim that there are only two known sealprints in the world. The other one is also in New York City, in the collection of the Metropolitan Museum of Art, entitled The Patrons of Regensburg, or St. Dionysius, St. Emmeram, and St. Wolfgang. It is similar to Coronation in that it is three-dimensional, but there is no media on the surface; instead it is bare paper.
I wonder whether similar objects exist in other collections, perhaps cataloged under a different term. Our Prints curator, Madeleine Viljoen, and I both reached out to colleagues and did not locate anyone who knew of any other prints of this type that have been discovered since 1926. The book Origins of European Printmaking mentions clay, limestone and tin molds have been found that may have "served in the production of small pictoral reliefs" and that "individual reliefs in papier mache have survived as decoration on...medieval wooden boxes...ceramic vessels or bells." Perhaps those objects are related to sealprints.
I am awed that I have had the opportunity to examine, treat, and re-house such a rare and interesting object. It came to conservation taped to a hinged mat inside a custom leather case. It is likely that the mat on the object pre-dates 1932, because it was shown in the picture used in the Mabbott article. The contours of the object do not appear to have changed, although it may have darkened.
This picture shows the verso of the print still attached to the mat. You can see pinpoints of light shining through some small holes. These holes are scattered throughout the paper, and may have been caused by insects. The worm holes, the carved appearance, and the dark brown coloration add to the impression that it is made out wood instead of paper.
This photograph, taken at .75x magnification, shows a crack in the top layer of paper, holes, and dust.
This photograph, also at .75x magnification, shows surface texture and areas of color.
To gently clean the surface, I dusted the contours with small, sponge-tipped artist brushes. A patch of white paper at the lower right, front, appeared to be an old repair. I toned it lightly with some watercolor so that it would be less noticeable. I inserted small amounts of paste between paper layers where they were delaminating; along edges and cracks.
I was able to remove most of the tape by inserting a microspatula under the edge and paring it away. In places where it was stuck more firmly, I covered the tape with a small poultice of wheat starch paste. After about two minutes, moisture from the paste penetrated through the paper tape carrier and softened the adhesive underneath so that I could clear it away with my spatula.
Below are pictures of the back before, during, and after treatment.
This is the front of the seal-print after treatment.
This picture shows the print in a new mat (attached only with small, Japanese paper hinges) and custom-made clamshell box.