PIDT Nobody actually really answered what it is. On certain coins - and my pet series the three cent silver are notorious for it - the dies are so overused that parts of the design literally migrate over time through the planchet. If you look at an 1852 3 cent silver you will often see a ghost of the C on the obverse or Star side and even more commonly a ghost of the star on the reverse. That's PIDT. If you ever see a high mint State coin with everything sharp and then this ghostly star, it's quite amazing. One was posted here a couple months back.
@Burton Strauss III so what does the acronym PIDT stand for? Pressed in design transfer is the only numismatic sounding thing I can make fit. What is it it’s killing me to know! Reed
Apologies guys I had really thought PIDT was common knowledge for most everyone on here since the majority of you are more knowledgeable than myself. PIDT is "Progressive Indirect Design Transfer” When the hammer die (obverse die) strikes the planchet, the force of the strike is transferred into and through the planchet and onto the opposing die (reverse or anvil die). Since the dies are slightly convex, the strongest force felt on the planchet is in the center of that planchet. However, in the case of the Lincoln cent, the center of the obverse die is incuse, so the area on the obverse die that experiences the first and strongest force is the field area immediately adjacent to Lincoln’s bust. Each strike transmits part of the force onto the opposing die. The area that transfers the most force onto the reverse die is the outline of Lincoln’s bust. This transferred force produces uneven metal flow in the reverse die, gradually creating a “ghost” image of Lincoln on the reverse die that shows up on the reverse of struck coins. Progressive meaning it's a die deterioration issue. Indirect meaning it happens through the coin planchet to the anvil die. Die: should be self explanitory what that is. Transfer: outline of Lincoln moves from the obverse hammer die to the reverse anvil die. It doesn't really happen much on thicker coins. The dies wear out or break before it happens but on the thinner coins there's enough force in the strike to tranfer the highest points of the design from the hammer die to the anvil die through the planchet. The thinner planchet don't absorb as much of the force as the thicker planchet do. Anyways. All good guys. It's a real acronym for a form of die deterioration/deformation.
@Burton Strauss III Thank you for clearing that up for me. It’s not on the lists I’ve looked at. Reed
FSASYA - Four score and seven years ago...……. Just being ridiculous! Acronyms are being carried too far. Blame it on lazy people and their dang cell phones. Chris
I'd like to point towards post #16 as apparently some decided to not read the thread and instead picked up a pitch fork. https://www.cointalk.com/threads/pidt.348731/#post-3786124 Thanks @John Burgess and @Burton Strauss III for explaining it.
If you haven't, read the rules. Abbreviations for unacceptable language will not pass. Check your email. Jim
PIDT is explained on error-ref.com as well. http://www.error-ref.com/progressive-indirect-design-transfer/
