Last One...promise...1968-S Lincoln Cent MD Vs. Hd

That's Machine Doubling on the devices. Notice how the devices are reduced in size and is shelflike in appearance? Think of it this way. It's like sliding a knife through butter and the butter smears.

Note the top of the 'S'. It is reduced. the area you are looking at is below the top of the device. On a doubled die, they are near the same height not flat shelf like.

RPMs like doubled die are enlarged not reduced. And if the date and the mint mark area affected the same, it is Machine Doubling. Just like your coin. The 1968-72 cents were filled with so much MD, it is almost harder to find one with out. Even the doubled dies average about 70% of them being machine doubled.

Note each of these are the major doubled die, but also have Machine Doubling. The machines create these from regular or doubled dies. Some Machine Doubling regular coins that year have a lot of MD.