Grease Grease Dies Dies (Whew, I Got 20 Characters)

The machines need grease to reduce friction. When this grease gets on the die, this prevents the devices to be struck up on the coin. Sometimes the dies are wiped down to remove the grease, that that just spreads a layer all around the die. So they will have to clean the die or use it until enough debris will accumulate and fall onto a coin. When this happens it is called a dropped letter.



These will be incuse in the coin and can be mirrored or look correct depending on how it fell on the the dies. This doesn't happen often though.

Grease is a very loosely used word for these errors. It could be anything, maybe buffing compound that doesn't get completely cleaned out of the die.

When I find grease on the rim area of coins, it seems to be clear. It is often mistaken as a chip. But running a toothpick shows the difference:


It is colorless and makes it appear that it is part of the coin.