Found this in a bankroll of a 2012 D penny and it seems like there are lines that are bumpy/bubbly on the reverse on the coin. It doesn't look like PMD to me. Not sure if this is a strike through or die crack. Can anyone help me?
*** Edited by Staff to Add Year / Mintmark / Denomination to Title. It's very important to have in the title. ***
Looks like roller lines are also visible, it is possible that the linear plating bubbles formed over the roller lines where there are small gaps or shallow trenches where zinc dust could be when the coin was plated over with the copper top coat.