They can tell by the tumbling marks on it. It is hard to show in photos, but there is a definite difference in the surface between that and the non proof
Only part of it is. There are two primary criteria for a coin to be a Proof: struck with specially prepared dies, and on a specially prepared planchet. What is usually considered as a secondary criteria is that Proofs are generally struck more than once. It's secondary because there are some examples of Proofs that were only struck once.
Someone help me out here. What's the difference in a Type 1 and Type 2 proof clad planchet? I thought that the differences were in the dies.
What I would love to know is why do the dates on the slab only say "1971-1976"? The Ikes were minted from 1971-1978. This coin was holdered in the last few years, not in 1976. So why don't the dates on the slab read as "1971-1978?" Were proof planchets made differently after 1976, thus not listing as 1971-1978 on the slab?
Must be a TPG thought up terminology be cause the mint calls them blanks until they leave the upsetting mill.
I learn and see something new every day on this site. Thanks for sharing. Now if I can only remember it for future brain reference ...
I believe my dime planchet is proof based on the mirror type surface (found in circulation), question is, does the rim gets "squared" during the die strike? :
....So I'd like to title this reply as Questions About Proofs that if Anyone Who Knows May Answer... What about the so-called 1913 5C Liberty Nickel Proofs? (Specially prepaped planchets?) I always assumed that they were regular planchets doubly struck. How far back does special prep of the planchets go? Curious. Are matte proof planchets prepared before striking?
They're not Proofs, never have been. The TPGs just suddenly decided to call them Proofs just like they call coins Specimens that are not Specimens, or SMS that are not SMS. Typically there is some polishing done to remove most planchet defects. Of course. All Proof planchets are specially prepared.
There may also be some difference in the cross section of the upset edge between business strikes and proofs that would allow a proof planchet to be identified. The mint uses differences in the upsetting to affect striking, rim fill etc.