Ok, I have been reading the chapter in The Experts Guide by Q. David Bowers on proof coins and I had some glaring questions jump up at me. How are proof dies polished to the point where you cannot see any hairlines in the fields? In reference to the first question, if you had a proof coin that exhibits 'shiny' portraits and devices versus the same in a cameo format, how do you polish said portraits and devices without seeing any hairlines. This is mainly a question on proof coins where the whole coin was polished and was a shiny proof instead of a frosted proof coin. My last question for now is if the mint was able to achieve such a feat, then I would assume it would be easy enough to replicate a similar effect on the coin itself to where a cleaning could 'enhance' a coin and be unnoticeable to all but the most savvy of collectors. Is this not a correct assumption? I mean I guess it wouldn't exactly be easy, but doable all the same.
It's pretty simple, and it's been explained many times. And to understand it you merely need to know what the process is. With Proofs, while the manufacturing method is very similar to that of making business strikes, it is still a different method. Proof planchets are polished before they are struck, business strike planchets are not polished. Proof dies are also polished, but they are polished to a much higher degree than business strike dies. The method for polishing dies, both Proof and business strike, is also simple. There is a machine that does it. There is a large zinc plate, a round disk about 10-12 inches in diameter. The zinc plate is attached to the machine and the machine spins the plate, very quickly. Above the plate the die is held in a press, when the press descends the flat face of the die is pushed against the face of the spinning zinc plate. But before that happens the face of the zinc plate is impregnated with a paste of diamond dust. In the first stage of polishing a course diamond paste is used. In each successive stage of polishing finer and finer grits of diamond dust are used. This results in a progressively finer polish polish being imparted to the face of the die. Until finally it is polished to a mirror like finish. But only Proof dies are polished to this mirror like finish stage, business strike dies are not. Regarding your second question, the coins themselves are never polished, the only things ever polished are the dies. Nothing is done to the coins after they have been struck. The reason you cannot see the any hairlines on Proof coins is because of the fineness of the diamond dust paste that was used to polish the dies. It works just like it does when you polish anything else to a high degree. You can't see any hairlines because they are so fine that they cannot be seen without high magnification. And the devices of a die are never polished, in fact quite the opposite is true. The devices have a rough finish and it is intentionally rough. It is this roughness of the devices that causes the cameo effect on a Proof coin. The roughness of the devices is created with one of several methods. In the old days they used to use an acid. They would take a die that had been hubbed and pour acid into the depressions of the devices. On a die the devices, legends, date, all of that are like holes, depressions, pressed down into the face of the die. The acid eats away at the metal of the depressions leaving behind a rough texture. A texture like very fine pebbles, pebbles so small that individual pebbles cannot be seen with the naked eye. So now when a Proof planchet is struck, you have the polished surface of the planchet, the polished surface of the die, and the rough texture of the devices on the die. The metal flows across the polished surfaces and is forced to retain its polished finish. The metal that flows into the depressions of the die meets the rough texture of the devices and is forced to take on that same rough texture. This rough texture is known as frost. So on the finished coin you have fields that are highly polished and devices with a rough texture, a frost. It is the contrast between these two very different finishes that creates the cameo effect. Now the reason that some Proof coins do not have the cameo effect is because as more and more coins are progressively struck the Proof die is progressively worn by the metal of the planchets flowing against it. And eventually this repeated metal flow wears the surface, the rough texture of the devices, smooth. This results in a Proof coin with no cameo effect and a slightly lessened mirror like finish on the fields. As to your last question, why such a thing cannot be replicated on a Proof coin after minting, well, to a degree it can be replicated. You can take a Proof coin that has no frost on the devices (these are known as brilliant Proofs) and artificially add frost to the devices. This is often enough to fool some collectors and dealers. But the artificial frost can be detected by those with the necessary experience to know it when they see it. With business strikes what you ask about cannot be done. That is because the luster of a business strike can only be created by the flowing of metal. Luster has unique qualities that cannot be replicated by any other means. And any disturbance of the luster is easily detected, by just about anybody.
Thanks Doug, very helpful explanation. I need to go back and look at my reference guide again and double check one or two things, but as always most everything you said makes sense. I suspected the answer, but like I said these particular questions just jumped up at me when reading that chapter last night, and its always nice to have further explanation and confirmation. Thanks Doug, keep an eye out for my follow up question after I glance through that chapter again.
Ok Doug I am going to quote verbatim what I read and hopefully you can see why I asked if you would be able to see hairlines on the devices (I actually assumed devices also referenced the bust or portrait, is this correct?) On page 375, the very last paragraph before the section on Matte, Sand Blast, and Satin Proofs, reads as follows: "Beginning in 1902, the first year of full production at the third Philadelphia Mint building, someone in the Medal Department decide to polish the portraits and certain other parts of the dies, in addition to the field. Accordingly Proofs of 1902 and most of 1903 have "shiny" portraits, as do some of the next several years" The part i underlined and bold type-faced is probably the single most important reason on why I asked the questions that I did. I just didnt see how if you polished the portrait that you wouldnt be able to see the hairlines. And if you were able to polish so finely before the coin was minted, would you not be able to replicate that process after the coin was minted and be able to hide any defects. I now understand that on Business strikes, you CANNOT polish a coin back to perfection due to the luster and hot metal flow that obviously cannot be recreated after minting. I am, however, still trying to figure out how you can polish the devices so finely that hairline arent readily visible across those coins that exhibit 'shiny' portraits instead of cameo ones. Also there is the very real possibility that Bowers' may have made a mistake in his wording or thinking.
Technically the word devices refers only to the portrait or other major component of the design. Legends, dates, and mottoes are referred to as such. But it is not uncommon for the sake of convenience in conversation to use devices to refer to all of it together. Doubtful, but I am curious as to why he worded it the way he did, specifically the phrase "someone in the medal department". I say that because usually people in the medal department have nothing to do with the coin department, they only work on medals. But then at the same time I have never heard of Proof medals - so maybe in this case they did. Perhaps your reading a bit more prior to those comments would add some clarification as to whether or not he is specifically talking about medal dies or coin dies when he says that. But, assuming he is talking about coin dies, that's what I get for using the word never, should have said almost never. Even if he is speaking of Proof coin dies, his comments make it pretty clear that what was done - polishing the devices of the die - was an exception to the rule and not usually done. Prior to 1902 all Proofs were pretty much just like those we are most used to seeing - mirrored fields & frosted devices. And, and as the book you are reading points out, it was not long after 1902 that the mint began experimenting with different kinds of Proofs, the matte and satin Proofs that we are familiar with. And in 1936 the mint returned to the mirrored fields and frosted devices type Proofs. As to how you cannot see hairlines on polished die devices, the reason would be the same you cannot see them on the fields of a Proof coin. You just have to use a fine enough polish compound so that they are too small to see. I also think it is important for you to understand that prior to 1973 Proof coins that actually had the cameo effect were the exception, not the rule. I am not referring here to the way they were made or intended to be, but instead I am referring to the actual coins themselves. As I described above, the only Proof coins that actually had the cameo effect were those struck with new or fairly new dies. For as more coins were struck the frost was worn off by metal flow the devices and the resulting coins had brilliant devices. But they were not brilliant because the devices were polished. The mint just didn't care enough to spend the additional money to re-frost the dies, or use new ones. They just kept on using the ones they had. It was a case of - these are good enough.
Thanks for your time responding Doug, I genuinely appreciate it. I didnt really know if it was proper etiquette or not to source any more than what I did the first time when I quoted the book, but since you asked for more clarification I am going to include the last two paragraphs of this section so you have a better context. Im sure Bowers wouldnt mind as this is all in an effort to learn more about numismatics. Here is what his book says: "Generally, in the 19th and early 20th centuries the production and distribution of Proofs was under the control of the Medal Department at the Mint, and different accounting procedures were in place. Often, Proofs werent included in the totals given in the regularly issued Annual Report of the Director of the Mint. In some instances Proofs were restruck, but no record was kept of these. Examples of the latter are provided by the Liberty Seated dollars of 1851 and 1853. Apparently, no Proof dollars were originally struck in either of these two years. Later in the decade there was a collector demand for such Proofs, and the Mint struck dollars of these dates either from old dies on hand or from new dies made up for the occasion. Proofs from the early years through and including 1901 generally have frosted portraits and other areas of relief, set against mirror fields. In recent decades some have called these cameo Proofs or deep cameo Proofs. However with few exceptions, all Proof coins of a given year and denomination are the same-either cameo or not. Most are. Beginning in 1902, the first year of full production at the third Philadelphia Mint building, someone in the Medal Department decide to polish the portraits and certain other parts of the dies, in addition to the field. Accordingly Proofs of 1902 and most of 1903 have 'shiny' portraits, as do some of the next several years" I think another thing that had been bugging me was that there was a particular series of proofs that i read about that were again also made by polishing the portrait/devices and that was the Mercury dime Proofs from 1936-1942, at least he seems to believe they were all polished. So this brings me over to my next question. How in the heck did they polish those devices without messing them up? Its not like theyre smooth like the fields are and easy to polish, i would assume they would need some sort of acid or fine sand, maybe blasting the diamond paste into them or something.
Thanks Greenie. I knew Doug would have some answers for me and I too thought it was a great question/series of questions. Like I said in my first post, after reading that one little paragraph I was hit with that 'hmm' moment and needed to find out some further information.
We do sometimes make light of father time but he is indeed most knowledgeable. Lots to impart and share, and much to be appreciated........
And the 'devil' should not have been a 'devil'. It should have been a 'happy face' most indeed..........
Agreed. Doug is a great resource to have around and I know I have learned much from him. I may not always post in threads he responds to, but I absorb a lot of what he says. He frequently has long thought responses and they usually make a ton of sense. He surely is a crucial member of our little community.
Well, I would usually not be one to contradict or doubt anything Bowers had to say about coins but I did a little more checking just to satisfy myself. So let me put it this way, anybody who searches the population records or looks at Heritage archives will readily see that there are more than a few Proof Cameos, in all denominations, from 1902 and succeeding years. And with mintage numbers often under 500 and always considerably less than 1000 for that period, I don't know any other way to say it other than it contradicts what Bowers said in his book. As for the Proof Mercury dimes from '36-'42, cameo examples of those exist as well. For me, the coins themselves are the best evidence we can ever have. They speak for themselves.
But you can see where I was coming from and ended up confused about this right? Also, what did you make of the Medal Department being the makers of Proof coins? Bowers said that they had been doing the Proofs for years, is this factual as well? One other thing, is there any way that you can start off with polished devices like Bowers claims and somehow in the run end up with cameo coins, or does that only work in reverse. For instance, is it possible to start with cameos early in the run and then fade out to polished Proofs near the end of the run? As for the cameo coins you found, do you believe they all could have been the result of manipulation that simulated the cameo effect like you described in your first response? I hate dragging this out, but I am really trying to get to the bottom of this and understand the process and history a little better. Maybe we need an 'Ask Me Anything' up here with Bowers, id sure like to hear his discussion on this with evolving theories since there is so much evidence pointing in both directions.
No I did not know that, it was new information for me. No, you couldn't, not unintentionally any way. The only way you can produce a Proof with cameo devices is if you intentionally frost the devices. On older coins that frost was produced by one of two methods. The devices of the dies were either sandblasted or treated with acid, depending on the specific time period you are talking about. And rather obviously both of these methods result in a rough surface and not a smooth, polished surface. As I explained above, that is exactly what happens naturally to Proof dies, all by itself due to die wear. And as I said this process continued until 1973. It was not until 1973 that the mint stopped allowing that to happen. The mint intentionally changed their policy and stopped using Proof dies as soon as they became worn enough to not produce a Proof coin with cameo devices. When the dies did become that worn they were replaced with new fresh dies so that all of the coins would be cameo. No. I've explained it as well as I can and like I said, the best evidence we have are the coins themselves. And when the coins contradict written material, well there it is right in front of you. It is up to each person to draw their own conclusions based on the evidence. As for asking him, I invited and asked Mr. Bowers to become a member of this forum several years ago. He declined. But it's a pretty simple matter to send him an email (his address is pretty well known - but don't anybody post it here !) and ask him questions yourself. He's always responded to me when I did.
