During a recent meeting, Stephen Emmel drew my attention to an article published by John Lawrence Sharpe in the proceedings of the International Conference on Conservation and Restoration of Archive and Library Materials, Erice, April 22nd-29th 1996.
In his paper, Sharpe studied the binding of certain Coptic codices. What is interesting is that he managed to convince William M. Voelkle, curator and head of the Department of Medieval and Renaissance Manuscripts, to accept the radiocarbon testing of a piece from the binding of the Glazier Codex (Acts 1:1-15:3 in the Middle-Egyptian dialect of Coptic). As far as I am aware, the results of the testing have passed unnoticed by Coptologists and scholars interested in biblical manuscripts. Here is the passage in which Sharpe explains the experiment:
“In consultation with W. Voelkle of the Pierpont Morgan Library, a piece of the wrapping band of Morgan G.67 approximately 17mm.2 and .25mm thick was selected for analysis. A piece of the wrapping band was chosen because of all the possible replacements, the most likely would have been the leather of the bands – those elements which would be represented by those pieces which are least likely to have been replaced. So the terminus post quam for the latest binding would be represented by those pieces which are least likely to have survived and most likely to have been replaced. So on the 18th of April 1994, a piece of the leather wrapping band was sent to the Eidgenössiche Technische Hochschule in Zürich (Institute of Partial Physics) for analysis for the AMS 14C dating. On the 19th of May 1994, the report for the piece of leather was returned from Dr. Georges Bonani with the following report: from Lab. No. ETH-12270, a sample of leather produced the AMS 14C Age [y BP] of 1’565 ± 45 with the results of δ13C[o/oo] of – 23.6 ± 1.1 with the calibrated Age [BC/AD] of AD 420-598 […]” (p. 383 n. 13)
Of course, all one can sensibly say after the radiocarbon testing is that the latest possible date for codex Glazier’s binding is 598 CE. However, as the manuscript is in a very good state of preservation, I find unlikely that the binding has ever needed to be replaced. Being the case that Codex Glazier is similar, especially in terms of format, to certain manuscripts from the Monastery of Apa Jeremias at Saqqara (which can be dated ca. 600 CE), I would opt for a late 6th century dating.
 J.L. Sharpe, “The Earliest Bindings with Wooden Board Covers: The Coptic Contribution to Binding Construction.” In: Erice 96, International Conference on Conservation and Restoration of Archive and Library Materials, Erice (Italy), CCSEM, 22nd-29th April 1996: Pre-prints, edited by Piero Colaizzi and Daniela Costanini, 2:381-400. 2 vols. Rome: Istituto centrale per la patologia del libro 1996.