Error? 1 Groschen, 1925 - Austria (Incuse Eagle!)

I believe this is called "ghosting" and is common on some types of coins. I had an Australian penny with the same effect, and while I think it's neat, I've been told it does not add any value.

Alan Herbert's The Official Price Guide to Mint Errors 7th Ed. has termed that ghosting as Heavy Design Transfer.

My understanding is that this is NOT a die clash, as that causes a raised, not indented image. Here is the response of a much more knowledgeable member from a similar thread in the Australian errors forum:

"Yep, it's "ghosting". Ghosting can happen when a coin made from a relatively hard metal is large and thin, one die is distinctly higher relief than the other, and the coin press is operating at high speed. As I understand it, It's caused by the metal inside the high-relief area "bouncing back", rather than flowing as intended. It's not considered a "mint error", since cause is ultimately a flaw in the design of the coin itself and/or in mint operating procedures rather than anything that went wrong with the minting process. Certain coin types are more vulnerable than others, such as British pennies pre-1928 and Australian pennies of George VI. British pennies were specifically redesigned in 1928 to try to minimize ghosting, with a smaller portrait and lower relief."

It's a form of Die Deterioration. Terms applied to it include "ghosting", "heavy design transfer", "internal metal displacement phenomenon", and "progressive, indirect design transfer". The last is the term I use. A vague impression of one die is transferred to the opposite die through the medium of many thousands of planchets.