I would appreciate your thoughts on the 1989 penny - the reverse side has a very faint stamping of the "States of" the top of the letter are normal height but they are barely visible below that. Is this anything of value?
Sorry not an error. During the minting process when the hammer die struck the planchet the metal filled Lincolns shoulders and coat thus not leaving enough metal to the recesses of the reverse. Look at the depth of the lower obverse device. Imagine the amount of material needed to fill the recess of the obverse die.
Looks like a little grease/debris struck-through on the reverse, and a lot of split plate doubling (where the thin coating of copper is moved showing the zinc beneath. I think that is what you are seeing.
You have to think about what you’re dealing with here: 1. It’s a crappy Zincoln plated with 8 microns thin copper. 2. Split-plate doubling where the strike pressure stretched that thin plating. 3. Die deterioration on reverse rim lettering (second T/STATES, among others). This is also known as a weak strike, but don’t confuse it with examples of struck through grease (STG), which can give similar anomalies. As @Dynoking explained, there just wasn’t enough metal available for the pressure applied and is very common for copper plated zinc (CPZ)…imo…Spark
I think all the responses offered are present. As noted, 12 o’clock on the reverse for Zincolns is a common location to find poorly filled devices. Not enough material moving to fill them out. However, the rim is defined in that area which suggests that the strike, while weak, was decent enough to define the rim. So for me, something else is in play. Looking at EPU, we see that some letters look properly defined while some are wider and flatter. That suggests the presence of grease. And the irregularities of the devices closest to the rim suggests a deteriorating die.
2 things: I think the upsetting process stacks metal at the rim, explaining the rim being okay for the strike. …and I think something else is in play too, meaning, why is the weak area always at the (STA)TES OF and EPU areas so much of the time? Is it the plating thinness by itself or is it maybe coupled with a tilted die alignment? I honestly do not have the expertise to say one way or the other or some other culprit…imo…Spark