Light-Microscopic and Spectroscopic Analyses of the Skin Materials Used in the Tefillin and Mezuzah Slips from the Judean Desert

Among the Dead Sea Scrolls is an assemblage of ancient tefillin and mezuzah slips—ritual artifacts composed of thin animal skins inscribed with passages from the Pentateuch. This paper presents the results of light-microscopic and spectroscopic analyses conducted on 26 tefillin and 8 mezuzot from the Judean Desert caves. These analyses provide the first opportunity to identify the following characteristics on these artifacts: animal species; skin thickness; skin layers present; tannage; side/s of skin with writing. In time, these characteristics took on ritual significance, especially in later rabbinic halakhah. A significant finding is that the ancient tefillin analyzed here were all written on extraordinarily thin splits comprising the papillary-dermal layer, while all the mezuzot were written on the full dermis.