Excellent write up, but I disagree with the part I quoted above, in particular the bold portion. It simply is not true. Yes, after a certain number of coins have been struck by a die, the die will show signs of wear. This wear can often appear as deepened lines in the surface of the die and yes these are called flow lines. But these deepened lines are not what creates or causes luster. The confusing part of this is that there are 2 different kinds of flow lines. And by using the same term to describe both, people often make the same mistake you are making. These are the two different things - flow lines in the metal planchet itself - and flow lines in the surface of the die caused by the repeated flowing of that metal across the surface of the die - or wear. Perhaps the easiest way to understand this difference is this. When a coin planchet is just sitting there waiting to be struck, the metal in that planchet is fixed in place, it is 100% solid and does not move. But when the planchet is struck, the metal does move - it flows almost like a liquid. But it is the stiffest and thickest liquid you can imagine. And it only moves because of the extreme pressure being forced upon it by the dies. You can think of flow lines as being the tracks left by the upper part of the metal as it moves across the lower parts of the metal. Now it is this movement of the metal itself, the flowing of the metal, that creates luster. And it has absolutely nothing to do with wear on the die. And when a die becomes worn and begins to show flow lines, the flow lines in the die will be higher and more distinct than the flow lines of the metal itself. They will appear as higher ridges and in fact be much like one the devices on the coin - a depression to be filled in by the flowing metal, only on a much smaller scale. And coins struck with a worn die will never, ever, have better luster than a coin struck with a new die. Again, this is confusing for a very good reason. 1 - the very first coins struck with completely unused dies are typically not very good examples. This is because the once the dies are keyed into the press they have to "settle" if you will. And quite often the spacing is then adjusted after just the first few coins are struck. These first struck coins are typically discarded and placed into the scrap pile for reprocessing. But once settled, the dies produce their very best coins, the coins with the very best luster and most complete details. These are the coins that are trully considered to be first strikes and they are struck with new dies. And that's the confusing part, because people will read this explanation in a book than think that only used dies produce the best coins. Well yes, the dies are used, on perhaps as few as 3 or maybe even a dozen coins while the settling and adjustments are made. But the dies do not receive any wear from this tiny number of coins. There are no flow lines in the surface of the die yet. These dies are still new. But people tend to misinterpret the explanation. And your last sentence, Proof Like coins do have cartwheel luster. Even Proof coins have cartwheel luster. But that luster has a different look, but it is not because there is little or no wear on the die. Proof coins have the look they do because of two things - the planchets are highly polished and the dies are highly polished. Today's Proofs are even different than the Proofs of old for modern Proof dies are chrome plated to add an even smoother and more polished surface, and to make them last longer. While the Proofs of old did not have this chrome plating and on them the cartwheel luster is more evident. By contrast, the surface of business strike dies are not polished as much and the planchets are not polished at all. And Prooflike coins come about as a result of new dies being used on an exceptional, but ordinary, planchet. For whatever reason, this particular planchet has a smoother surface than normal planchets. As I have explained many times before, if you think of luster as looking like this - /\/\/\/\/\/\/\/\ - it then becomes easier to understand. And different types of luster caused depending on the height of those lines. This explains the difference is luster on all our coins. Like the difference in luster on Peace and a Morgan. A Jeff and a Liberty; a Walker and a Frankie. A business strike and a Proof. Luster is luster, and no matter what the particular look it may have, in every single case it is always caused by the very same thing - the actual flowing of the metal in the planchet, nothing else.