The AATCC Manual of International Test Methods and Procedures is a compilation of test methods, evaluation procedures, and monographs developed by AATCC Research Committees. The 2026 Volume 101 contains 3 new standards, 24 revised standards and 4 editorially revised standards. One method has been withdrawn and removed from the manual. The standards in this volume of the Manual of International Test Methods and Procedures were current as of August 2025. New standards that have been added and other important changes made since the last volume are summarized within.