- Here's a copper-colored or copper-plated nickel that NGC is
calling "improperly annealed".
I thought "improperly" or "poorly annealed" planchets were supposed to
be brittle or poorly struck (or both), not discolored.
Nobody really knows where the copper color/plating comes from, so I
suppose "improperly annealed" is just as much of a guess as "copper
wash" and "sintered plating". But it just adds to the confusion.