The Rosenberg Rotulus arrived in the paper lab of the Canadian Conservation Institute (CCI) in 2019 to undergo conservation treatment to stabilize its condition. The ilan was inscribed with iron gall ink, a material which is often highly unstable. The deterioration of the ink lines was causing the manuscript’s rag paper to become increasingly brittle to the point that unrolling or re-rolling the manuscript risked exacerbating damage and loss. In late 2020, the rotulus returned to the JPL Archives after conservation treatment, including design of a custom box and roller rod system to aid in handling and access. CCI paper conservator Crystal Maitland will speak about the materials used in the manuscript’s creation, and about how examining them with different lighting methods helps tell us about their structure and composition. She will discuss how the rotulus’ condition and materials informed the conservation treatment process, and finally describe the preservation strategies used to help ensure the ilan’s continued longevity.