The crucial properties needed for forensic casting materials are reliability, accurate reproduction of detail without damage to the mark, ease of use, reproducible cure rate, resolution of detail, dimensional stability, and cost-effectiveness. None of the current casting materials can produce ultra-thin replicas of marks from irregular surfaces. However, the compound Isomark X1 Black satisfies all the criteria involved in forensic casting applications. Its application takes place via a standard hand-operated gun dispenser or in a spray format. The use of this product with latent fingerprints on the barrel of a shotgun was successful and resulted in no deterioration of the detail after 6 months. The analysis concluded that this system is easy to use and produces high-resolution replicas that are strong, flexible, and dimensionally stable over time. Photographs, author contact information, and 13 references