The zinc-composition Lincoln cent (1982 to present) is unusual in that it is the only United States coin to be plated. The copper plating is applied to the zinc core after it passes through the upset mill, a step that converts a blank into a planchet. While this process would ordinarily preclude there being any plated blanks, there are a few exceptions. Three plated cent blanks are known.
The zinc core is also unique in that it is never heat-softened (annealed). This also holds true for the plated planchet.