Posted 01/23/2018 5:46 pm
Prior to 1990, the mint marks were added to the dies by hand. A punch was used to punch them into the die's surface. Some mint marks were punched deeper than others, which left a more distinct mint mark on the coins minted with that die. A lighter punch would leave a thinner, lighter mint mark.
Another cause for thinner mint marks is die polishing. Since the mint mark is incuse on the dies, when they are polished some of the surface area is removed but the incuse mint mark remains, but thinner, just as if it had been lightly punched.
Another cause for thinner mint marks is die polishing. Since the mint mark is incuse on the dies, when they are polished some of the surface area is removed but the incuse mint mark remains, but thinner, just as if it had been lightly punched.
