Understanding a die will help here is one:

Note the flat area on the top of the die. That is called the field area. On the coin, that is the background of the devices and design. Note the area marked rim? There is a small channel around the die that is lower than the fields. So what does that mean to a coin? Dies are negatives. If something is lower on the die, then they will be raised on the coin. If it is lower than the field, it will be raised higher on the coin. Note the mirrored letters on the die, they are incuse on the die, but raised on the coin. The field. If a part of it breaks off leaves a void.

This void on the die will be filled with as much material is allowed during the strike. leaving a Cud above the field area.

Not how this Cud is inside the rim area. Thus that circular area of the die face, if broken off will raise hight then the face and often above the rim when the rim chips off with contact will the collar:

But like your coin if that area is raised it us just a baby rim chip. It only affect the rim area and not the die face.

Often they are larger than your coin. But the metal only goes into the void so far and looks curled at the top on the coin.
So the difference between a rim Cud and a Die Cud are that the field area is affect on a Die Cud and something the rim breaks off a bit. On a rim Cud just that lower channel get broken off and that is why it is taller than the rim. Hope this helps
CoopHome : Difference between Die Cud rim Cud?

Note the flat area on the top of the die. That is called the field area. On the coin, that is the background of the devices and design. Note the area marked rim? There is a small channel around the die that is lower than the fields. So what does that mean to a coin? Dies are negatives. If something is lower on the die, then they will be raised on the coin. If it is lower than the field, it will be raised higher on the coin. Note the mirrored letters on the die, they are incuse on the die, but raised on the coin. The field. If a part of it breaks off leaves a void.

This void on the die will be filled with as much material is allowed during the strike. leaving a Cud above the field area.

Not how this Cud is inside the rim area. Thus that circular area of the die face, if broken off will raise hight then the face and often above the rim when the rim chips off with contact will the collar:

But like your coin if that area is raised it us just a baby rim chip. It only affect the rim area and not the die face.

Often they are larger than your coin. But the metal only goes into the void so far and looks curled at the top on the coin.
So the difference between a rim Cud and a Die Cud are that the field area is affect on a Die Cud and something the rim breaks off a bit. On a rim Cud just that lower channel get broken off and that is why it is taller than the rim. Hope this helps
CoopHome : Difference between Die Cud rim Cud?


















