Project: Analysis on the Covers of Antiphonary
Object’s Title: Antiphonarium for Matins
Creator: Catholic Church
Country of Origin: Spain
Date: est. 16th century
Owner: Special Collections Research Center, University of Chicago Library
Ann Lindsey, Head of Conservation, University of Chicago Library
Rosie Grayburn, Winterthur Associate Scientist and Affiliated Associate Professor
This bound manuscript has thick wooden boards covered with dark brown leather, likely ox or bovine skin considering the book’s size. The leather on the covers and spine is blind-tooled with large brass bosses. While the textblock is estimated to date from the 16th century, it appears to have been resewn and is likely not in its original binding. According to Melina Avery’s treatment proposal, the repairs seem to date to the late 19th or early 20th century. The focus of the analysis is a mysterious substance applied to the blind-tooled areas. These areas feel slightly tacky to the touch and have accumulated significant dust and dirt, particularly on the front cover. Under UV light, the tooled areas fluoresce pale yellow-orange, while the rest of the leather does not fluoresce.
The purpose of this analysis is to identify the sticky, fluorescing substance on the leather cover. Since the unknown material is applied solely to the tooled areas and fluoresces yellow under UV light, it is suspected to be egg glair. Historically, egg glair was commonly used as a heat-activated adhesive to attach metal leaf to covering materials. After blind tooling was completed, egg glair was typically applied to the recessed impressions, and metal leaf was then set using heated finishing tools and pressure.
However, there are conflicting findings. First, no gold or metal leaf is present on the cover. Second, the substance appears to have been applied rather carelessly over the entire tooled area, not precisely within the recessed impressions. Although it is noted in Roberts and Etherington (1982) that egg glair can sometimes be sponged across the entire tooled surface, the more common practice is to apply it only to the recesses.
Given these observations, it is inconclusive whether the yellow fluorescing material is indeed egg glair. Further examination using analytical tools, such as Fourier-transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS), will be necessary to identify the substance. These analyses could also reveal whether the binding was intended to have gilt decoration, providing insight into the craftsperson’s intentions. This information would be valuable for researchers, educators, and exhibition planners, as the book is frequently requested for classes and may be featured in a future exhibition.