Question about modern brilliant (mirror) vs cameo proofs.
RWB
Posts: 8,082 ✭
I was reading Rick Tomaska’s book on Franklin halves last night, and a question about cameo vs brilliant proofs crossed my mind.
As Rick explained, a proof die was lightly etched in 5% nitric acid, then the fields (raised on the die) were buffed to a high polish. The inscriptions and portrait, being recessed on the die retained their etched surface. When struck on a polished planchet, the result was a mirrored field with frosty devices – a cameo proof.
During use, friction gradually smoothed the etched portions, resulting in less “frosting” on the devices, and less contrast between the fields and portrait/lettering. After a relatively small number of coins had been struck, the etched areas were completely obliterated, resulting in coins with a uniform mirror finish – the vast majority of all Franklin proofs.
My question is about the last part of this scenario. As etched metal is abraded and moved , the rough etched character would certainly be changed to something smoother. But it should produce something similar to a satin or even lustrous surface. How and why would it transform into a mirror similar to the polished fields? Were the blanks so highly polished that they transferred their mirrored surface to the formerly etched portions of the die? Were the dies simply polished all over after the initial use?
As an analogy, most agree that proof-like Morgan dollars result from polishing or lapping of a die. As the die is used the mirror gradually degrades into a smooth, and finally lustrous surface. That is, the surface moves from greater order (polished) to lesser order (smooth) – entropy.
For the modern proof coin description (above), it would seem that moving from etched (greater order) to smooth (lesser order) to mirror (greater order) violates basic physics.
Thoughts?
As Rick explained, a proof die was lightly etched in 5% nitric acid, then the fields (raised on the die) were buffed to a high polish. The inscriptions and portrait, being recessed on the die retained their etched surface. When struck on a polished planchet, the result was a mirrored field with frosty devices – a cameo proof.
During use, friction gradually smoothed the etched portions, resulting in less “frosting” on the devices, and less contrast between the fields and portrait/lettering. After a relatively small number of coins had been struck, the etched areas were completely obliterated, resulting in coins with a uniform mirror finish – the vast majority of all Franklin proofs.
My question is about the last part of this scenario. As etched metal is abraded and moved , the rough etched character would certainly be changed to something smoother. But it should produce something similar to a satin or even lustrous surface. How and why would it transform into a mirror similar to the polished fields? Were the blanks so highly polished that they transferred their mirrored surface to the formerly etched portions of the die? Were the dies simply polished all over after the initial use?
As an analogy, most agree that proof-like Morgan dollars result from polishing or lapping of a die. As the die is used the mirror gradually degrades into a smooth, and finally lustrous surface. That is, the surface moves from greater order (polished) to lesser order (smooth) – entropy.
For the modern proof coin description (above), it would seem that moving from etched (greater order) to smooth (lesser order) to mirror (greater order) violates basic physics.
Thoughts?
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Comments
and it sets us apart from practitioners and consultants. Gregor
- The great student of die states, Del Romines, observed that fresh dies have imperfections and even develop minute die cracks that show on the very early strikes but shortly the dies begin to smooth over as they go through "Very Eartly Die State". It is after this smooting out that the very earliest die flow lines make their appearance which cause luster to begin to bloom in early EDS, all of which happens in the first few tenths of a percent percent of a circulation die's life.
- BS silver Ikes seem to start out frosted all over, then smooth over and can even become proof-like before developing visible flow lines.
As you know, I've postulated that Ike proofs were "re-treated" five or ten times during their 1500 coin life time due to Gasparro's insistance that a high percentage of Ike proofs had to have cameo contrast (to justify their $10 price): each re-treatment would both re-frost devices and re-polish the fields, especially the critical areas of the field close to the major central device where frosting was likely to slop over onto the field The numbers are consistent with cameo contrast holding up for just a handful of strikes, my guess is fading to smoothafter 50 to 200 coins struck.
So, I think we're dealing with a very early die phenomenon, a sort of stabilization with rapid smoothing that is entirely different than the more gradual roughening of a dies surface due to "flow lines".
All of this is, of course, MVHO as there is a paucity of mint records of which you are keenly aware! Rob
Questions about Ikes? Go to The IKE GROUP WEB SITE
appearance of the struck coin but the strike will bring up luster even on
the dullest planchet. As the etching wears off it is simply replaced by
highly lustrous surfaces as the polished planchet is struck repeatedly
by the polished die surface.
Modern proof dies (since ~ '83) are chrome plated so they'll retain the
frosting.
Brand new dies will retain their initial characteristics for about a dozen
strikes in cu/ ni clad. These are extremely beautiful coins usually and
they can have significant luster but usually it will be quite suppressed.
These are virtually impossible to find in mint rolls due to the high usage
for each die but are relatively easy in mint sets where most dies are
used for only about 30,000 strikes.
From this I gather chrome plated Proof dies were used from '78 on for the Kennedy and '79 with the new small Dollar.
This timing is relevent to Ikes as proof re-treatments may not feasible on Chrome plated dies and all the Ike proof years have examples with generous "fade" consistent with X5 to 10 re-polishings including the '78s.
Raises an interesting issue with the the SBA "Small Star" Proof Variety recognized by Breen: a logical explanation of the small star (third star counting to our left from bottom left star) is proof die polish: Alan Herbert also suggests this possibility.
Do you know if chrome plated proof dies were ever polished after being chrome plated ? Wouldn't the veneer be worn through and show up like a topo map line? Are we left with the conclusion that any polishing of SBA proof dies was done before the chrome plating? Rob
Questions about Ikes? Go to The IKE GROUP WEB SITE
Rob
Questions about Ikes? Go to The IKE GROUP WEB SITE
So far, there are two alternatives:
1) The mirror surface of planchets was transferred to the originally-etched features, resulting in fully mirror proof coins.
2) After deterioration of the original etching, dies were polished all over, resulting in fully mirror proof coins.
In Moderndollarnut’s scenario, frosted devices could be maintained only by occasionally re-etching the entire die, then polishing only the field.
(Yes, entropy makes sense – order moves to disorder in the absence of external force. Etched metal is a deliberately ordered state, polished metal is a deliberately ordered state; metal striking metal would move either to a less ordered state.)
<< <i>I believe chrome plated dies weren't reworked. >>
I might be wrong, and it would take some digging to try and track down the reference - but I think I saw somewhere that the chrome plated dies are reworked - the chrome plating is stripped off, work is done, and then dies are replated.
<< <i>Consider also, the problem of 1936 proofs. Apparently the very first few struck were mirror proofs and that the next ones were more satin-like in surface. If this is correct, then it implies the original polished die surfaces degraded to a smooth surface…If that occurred, there is no way to return them to mirror except by re-polishing the dies.
So far, there are two alternatives:
1) The mirror surface of planchets was transferred to the originally-etched features, resulting in fully mirror proof coins.
2) After deterioration of the original etching, dies were polished all over, resulting in fully mirror proof coins.
RWB, I don't know how one could polish the entire surface of a die? Sharp incuse devices could not be reached by any polishing technique I know of (except striking proof planchets, LOL!).
Also, our thinking about Ikes has advanced a bit: we are now considering whether frosting and re-frostings of Ike proofs was done by a mineature hand-held "sand-blaster" device which could more or less target incuse devices so field re-polishings were more touch-up than uniform re-polishing of all the fields each time.
I agree with CladKing's point that proof planchets would tend to smooth out proof dies - the question is how fast and whether the historic record of 10 to 20 strikes removing all cameo held throughout the Ike era or if the cameo produced by our presumptive particle-blasting created a somewhat longer-lasting cameo than the older technique of acid dipping. Rob
Questions about Ikes? Go to The IKE GROUP WEB SITE
<< <i>
I agree with CladKing's point that proof planchets would tend to smooth out proof dies - the question is how fast and whether the historic record of 10 to 20 strikes removing all cameo held throughout the Ike era or if the cameo produced by our presumptive particle-blasting created a somewhat longer-lasting cameo than the older technique of acid dipping. Rob >>
There's enough cameo on Ikes to believe the "sand" blasting did extend the
life of the cameo effect. The cu/ ni Ike planchets would have been much hard-
er on dies than silver planchets yet cameo Ikes are not difficult to find in most
cases. The sand blasting was repeated when worn off many times. Some of
the Franklins are tough enough in cameo to believe that this wore off quite ra-
pidly. One wonders if every proof die recieved the etching.
My reference to the "new die" effect wearing off in about dozen strikes applied
to cu/ ni clad business strikes. This is estimated from the fact that it takes a-
bout 2500 mint set quarters to find one struck by a new die and mint set quart-
er dies average about 30,000 strikes. Other denominations seem fairly similar
since die life increases with softer metals. I'm not sure if I've seen enough Ikes
to know how often these appear from new dies, though.
I would think that a die could never become more polished than the average for blanks, if that is how it occurs. If the mirror surface is from deliberate polishing, then, as you mentioned, how does it become so uniform.
Maybe there's an experienced metal worker or proof die maker sitting out there in internet land with the answer.
<< <i>The core of my question remains: “How do we get mirror surfaces on all parts of a proof coin?” Many 19th century proofs are fully brilliant.
I would think that a die could never become more polished than the average for blanks, if that is how it occurs. If the mirror surface is from deliberate polishing, then, as you mentioned, how does it become so uniform.
Maybe there's an experienced metal worker or proof die maker sitting out there in internet land with the answer. >>
I could be all wet here but would think that any wear on a die
would not have dramatic effect on the reflectiveness of the struck
coin. It's more the polishing of the planchet being seen than die
condition.
<< <i>
<< <i>The core of my question remains: “How do we get mirror surfaces on all parts of a proof coin?” Many 19th century proofs are fully brilliant.
I would think that a die could never become more polished than the average for blanks, if that is how it occurs. If the mirror surface is from deliberate polishing, then, as you mentioned, how does it become so uniform.
Maybe there's an experienced metal worker or proof die maker sitting out there in internet land with the answer. >>
I could be all wet here but would think that any wear on a die
would not have dramatic effect on the reflectiveness of the struck
coin. It's more the polishing of the planchet being seen than die
condition. >>
CladKing, you ain't even damp... The Ike Group has pulled from BU rolls and circulation hundreds of 1971-D Ikes struck on clad proof planchets (yes!). The most reflective easily reach DMPL status except the usually present underlying die-flow lines break up readable reflections. When present, the shine is uniform across both sides of the coin. My most outrageous examples were struck by VLDS dies, no surprise as dies spend more than half their life in VLDS.
Roger, as to the devices becoming as shiny as the fields with time (classic proofs), all you need is Romines' observation augmented by the dies repeatedly striking proof planchets and thus taking on the characteristics of those planchets. (I assume classic proof planchets were proof-like?) Rob
Questions about Ikes? Go to The IKE GROUP WEB SITE
I've long believed that degree of planchet polishing is the largest single
component of what collectors refer to as "eye appeal". The mint does not
vary any processes a great deal during the minting year usually but the
texture of the metal used to cut blanks does vary more depending on nu-
merous factors when it is rolled. Some coins have terrible surfaces simply
because this metal is rough. The most dramatic example might be the 1942
aluminum coinage from one of the Yugoslavian countries. These can look
attractive but luster is usually absent or very suppressed. Closer to home
is the '69 quarter. These can often be lustrous enough but usually retain
planchet scratches. "81-P quarters also have poor surfaces though some
of this might be caused by die conditions.
Sometimes planchets can recieve a sort of partial polishing and these will
often result in coins with booming luster or an undefinable "eye appeal". If
a coin is gem in all regards and has this luster then it just looks better than
comparable coins without it.
There are many ways that these special planchets get in the system. Usu-
ally it will just be a sheet that was smoother than most but proof planchets
and other fully or partially polished planchets can get in the stream. I've al-
ways suspected that many of them are simply those which got caught up in
the machinery and polished from bouncing around. They are usually too
scarce for it to be a systemic "failure" and they come in a range and this im-
plies that polishing was not intentional.
<< <i>
The Ike Group has pulled from BU rolls and circulation hundreds of 1971-D Ikes struck on clad proof planchets (yes!). The most reflective easily reach DMPL status except the usually present underlying die-flow lines break up readable reflections. When present, the shine is uniform across both sides of the coin. My most outrageous examples were struck by VLDS dies, no surprise as dies spend more than half their life in VLDS.
Rob >>
I've seen a few of these. I even picked one up for $1 because the owner thought it was counterfeit.
Now the question arises of why they would have polished cu/ ni planchets in 1971.
Now the question arises of why they would have polished cu/ ni planchets in 1971."
Cladking, are giving me a hanging curve ball? If so, THANKS!
We've published substantial evidence that the Friendly Eagle Variety reverse was very probably intended to strike a low relief 1971-S clad proof. Among the key features are the elevated Earth (to prevent die polishing erasing its cameo or even features) to the highly articulated details which harkened back to a time when the proof was sharper than the corresponding circulation design.
Also the FEV's linked islands overly precisely the incuse mega island of the high relief design (used on the '71-S Silver Proof) and Florida points more to the South than any low reliev Ike and exactly in the direction the high relief FL points.
All of this is circumstantial until one adds the remarkable prevelance of obvious proof planchets among '71-D Ikes:
- It is well know that the S Mint threw its reusable trash to the Denver Mint including rejected planchets and strip, even the out of spec stuff (how Denver hated being the recipient of the S Mint's rejects and trash!);
- The typical '71-D Ikes struck on proof planchets have NO, that is, ZERO planchet chatter: for the greater part, these planchets were not "proof-like" they were PROOF, period;
- Also, the reflective brilliance is continuous on the inside of loops of letter and number devices, and, likewise on the tops of all devices, both impossible to accomplish on either die or hub and of course impossible to accomplish on a single coin let alone on millions unless the planchets themselves were proof polished.
- Lastly, as mentioned above, the proof surfaces are present independent of die state. 90% or more of all 1971-D Ikes were struck in MDS through VLDS (ie, when die flow lines blossom from just visible to ruts), so it is only the occasional early MDS and rare EDS Ike with no significant flow lines that could have their reflectivity from new die strikes and these 71-D's will have Planchet Chatter.
Now I have to admit I fibbed a bit about NO planchet chatter: roughly 10% of these proof planchet 71-D's have a touch of planchet chatter. No big deal as about 10% of proof planchets are rejected for chatter-like damage and can be pulled from the annealing stage or the steel-pellet polishing stage or from the final planchet inspection stage and all of these would have gone to Denver also.
Planchet chatter is key. As you work with Ikes extensively you learn to recognize just how pervasive PC is throughout the series. Thus when it is flat-out (sorry) not there, it gets one's attention.
Anywho, I would give 10 to 1 odds that the FEV was intended for a '71-S Clad Proof. and. even odds that it was the original low relief design for all low relief Ikes including the clad proof (thus satisfying a long-standing Mint policy that a series proof has the same basic design of its circulating coin).
When the clad proof project fell through, Gasparro probably struck new low relief hubs and modified the design precisely for greater visual impact in the context of low relief and the profound die wear he now knew he had to deal with. Thus, larger stars and considerable artwork to increase feather definition and of course the return to the Eagle's Brow line he had to give up to get his original design approved! Rob
Questions about Ikes? Go to The IKE GROUP WEB SITE
<< <i>(Cladking) "I've seen a few of these. I even picked one up for $1 because the owner thought it was counterfeit.
Now the question arises of why they would have polished cu/ ni planchets in 1971."
Cladking, are giving me a hanging curve ball? If so, THANKS!
We've published substantial evidence that the Friendly Eagle Variety reverse was very probably intended to strike a low relief 1971-S clad proof. Among the key features are the elevated Earth (to prevent die polishing erasing its cameo or even features) to the highly articulated details which harkened back to a time when the proof was sharper than the corresponding circulation design.
Also the FEV's linked islands overly precisely the incuse mega island of the high relief design (used on the '71-S Silver Proof) and Florida points more to the South than any low reliev Ike and exactly in the direction the high relief FL points.
All of this is circumstantial until one adds the remarkable prevelance of obvious proof planchets among '71-D Ikes:
- It is well know that the S Mint threw its reusable trash to the Denver Mint including rejected planchets and strip, even the out of spec stuff (how Denver hated being the recipient of the S Mint's rejects and trash!);
- The typical '71-D Ikes struck on proof planchets have NO, that is, ZERO planchet chatter: for the greater part, these planchets were not "proof-like" they were PROOF, period;
- Also, the reflective brilliance is continuous on the inside of loops of letter and number devices, and, likewise on the tops of all devices, both impossible to accomplish on either die or hub and of course impossible to accomplish on a single coin let alone on millions unless the planchets themselves were proof polished.
- Lastly, as mentioned above, the proof surfaces are present independent of die state. 90% or more of all 1971-D Ikes were struck in MDS through VLDS (ie, when die flow lines blossom from just visible to ruts), so it is only the occasional early MDS and rare EDS Ike with no significant flow lines that could have their reflectivity from new die strikes and these 71-D's will have Planchet Chatter.
Now I have to admit I fibbed a bit about NO planchet chatter: roughly 10% of these proof planchet 71-D's have a touch of planchet chatter. No big deal as about 10% of proof planchets are rejected for chatter-like damage and can be pulled from the annealing stage or the steel-pellet polishing stage or from the final planchet inspection stage and all of these would have gone to Denver also.
Planchet chatter is key. As you work with Ikes extensively you learn to recognize just how pervasive PC is throughout the series. Thus when it is flat-out (sorry) not there, it gets one's attention.
Anywho, I would give 10 to 1 odds that the FEV was intended for a '71-S Clad Proof. and. even odds that it was the original low relief design for all low relief Ikes including the clad proof (thus satisfying a long-standing Mint policy that a series proof has the same basic design of its circulating coin).
When the clad proof project fell through, Gasparro probably struck new low relief hubs and modified the design precisely for greater visual impact in the context of low relief and the profound die wear he now knew he had to deal with. Thus, larger stars and considerable artwork to increase feather definition and of course the return to the Eagle's Brow line he had to give up to get his original design approved! Rob >>
Ah, that makes sense. There's a lot here I didn't know.