Toned 1976 S Lincoln Cent

Acid is NOT used during the stamping operation. The die devices are "treated" with acid to give the frosted effect and then moved into production. No chemicals come into contact with the planchets during coining.

Thank you for clarifying Thad. If I understand correctly, the chemical is applied pre-strike & then cleaned solely to give a portion of the die a rough texture. This effect is lessened as the die is used repeatedly, I assume due to the pressure of the contact with the planchet?

This would make a great deal of sense as I've read previously that sandblasting was used in the past, presumably to achieve a similar result.

I watched an informative video from the Discovery channel last night regarding the process @ what I assume is a Canadian facility. Very educational! I'll post that in a separate topic for others to enjoy. (See it here)