*** Edited by Staff to Add Year / Mintmark / Denomination to Title. Titles are Important! ***Hello everyone one. I am having a hard time with DD since I am a beginner all coin look alike to me. What is the easiest way to tell if a coin is a DD or
Machine Doubling? I have searched for many articles but haven't been able to spot or learn the difference. For example, I am posting a 1971 S penny that appears to look like a DD. Thank you.


