SI Correction.

This document is a correction to the supporting information for an article on the preservation of cellulose in ancient textiles. The authors note an error in Table S2, which has been corrected online. The article discusses the analysis of fibers from archaeological sites in Turkmenistan, Pakistan, and Iraq using synchrotron X-ray microtomography and μ-FTIR spectroscopy. The document provides technical information about the methods and equipment used in the study, including second-harmonic generation microscopy and energy-dispersive X-ray spectroscopy. It also includes tables and figures related to the analysis of compounds found in archaeological contexts, specifically copper artifacts from Nausharo and Tello. The information can be helpful for researchers studying similar topics. [Extracted from the article]