Grease Mold Doubling/Filled Die Doubling
Associated with filled die errors, grease mold doubling or filled die doubling occurs when the grease or other die fill material comes loose from a recessed part of the die and migrates to the flat field area, where it gets impressed into the remaining gunk that is on the die, forming a secondary image of the device that is raised on the coin's surface. So far this type of doubling has only been found on cents from the mid to late 1990's.
Photo By Amos811
Photo By Amos811
Photo By Amos811
Photo By Amos811
Photo By Amos811
Photo By Amos811