This training was presented as a part of the National Center on Forensics Conference at George Mason University on August 10th, 2023. In this session, NIST Senior Forensic Science Research Manager Rob Thompson and FBI Supervisory Physical Scientist/Forensic Examiner Michelle Machalka introduce the concepts of firearm and fingerprint impressions. This session is useful for understanding what impressions are, how they transfer, how they are collected, how they are analyzed, and what challenges analysts encounter.