Building an Error Type Set

Submitted by JonSullivan on Sat, 05/30/2015 - 14:50

Building An Error Type Set


Jon P. Sullivan



The error type set collection is based on the minting process, with the ultimate goal of finding one of every type of mistake that can happen during the minting of coins. This approach is different from collections whose acquisitions are based on a special date, a particular denomination, or simply how “neat” and “eye-catching” the error is. My approach with my own collection is to build an error coin type set which will comprise one of every error and variety type known on U.S. coins, as well as error types which are unknown on U.S. coins, and which can only be found on foreign coins. Error type sets are a great way to build an error coin collection because the method of collecting maintains a certain degree of uniformity, order, and has a clear goal in mind, and yet has enough change and customization to satisfy the collector who is more interested in the error’s eye-appeal and look, than in creating a date set of the same error and just “filling holes.”


Although with a type set, you will be looking to acquire one of each error type, you will still be free to customize your set in a number of ways: how dramatic the error is, or by choosing to stick with errors on just a few series of coins, such as Jefferson, Buffalo and Liberty nickels, or perhaps by picking only one series, such as Lincoln cents. There are many ways you can choose to expand your type collection as well, whether by adding a certain number of multi-error coins, or by getting the same error type, but on several different denominations. So instead of simply getting one representative example of say, an off-metal, you would get one of every off-metal combination known on every denomination. However you build your type set, there are some guidelines which I am using in assembling my own collection, and which you might find helpful when assembling yours.

double-struck Lincoln cent

The first guideline is that the error must be on a U.S. coin, except for error types which are only created on foreign coins. It is not necessary to stick with U.S. coins as the basis for building your collection, but it is simply a personal preference of mine to choose U.S. when available. This is because I love our nation’s history and also the designs of much of our coinage- and there’s a cultural connection which makes the designs and their historical nature relevant to me as an American. Another reason is that U.S. errors tend to hold their value, and also appreciate in value, better than foreign errors. Not that I don’t collect for the enjoyment, but it is wise to keep the financial implications in mind, especially since coin collections can quickly become large investments as they grow over time. Despite my seeking U.S. errors when they exist for an error type, one error type known on U.S. coins which I will not be placing in my collection, is the Mule error. If you are in the habit of reading the various headlines in the major coin publications, you will understand the reason I make this exception--It is very expensive! The most affordable example costs in the neighborhood of $40,000! On the other hand, a foreign mule error, such as the New Zealand/Bahamas mule, can be had for less than $100. Although most error types are known on U.S. coins, I will also have to look abroad in order to acquire a few certain error types which simply do not occur on U.S. coins. They are a fairly small number, and most occur on bimetallic coins or coins with center holes.


My second guideline is that the coins must clearly demonstrate the represented error type and must have exceptional eye-appeal as a whole. For instance, I would not wish to put a Washington quarter struck 5% off-center in my collection as an example of an off-center, because this is a very small percentage off-center and not very attractive. Instead, I would choose a coin struck 30-70% off-center, because in this case you can tell at a glance what denomination and design of coin it is, as well as the glaring fact that it is off-center. This is true of all the error types--you want to be able to easily tell what kind of coin it is, and also clearly see that the coin is the error type it represents. In future articles I intend to cover in more depth what features and characteristics to look for in the different error types in order to choose a quality type example.


The third guideline is that the coin must be in excellent condition, with no major problems, and in an overall superb state of preservation. If you are not limiting yourself to a particular series or denomination, this should not be a problem as you can shop around in less expensive series, if necessary, to find a coin which not only meets the second guideline, but is also in nice condition. Choosing quality is the best way to collect, so for example rather than buying a badly corroded Buffalo nickel struck 50% off-center for $450, which is a super error, but is in bad condition, you could buy an attractive alternative such as a mercury dime struck 30% off-center in AU-58, which would cost roughly the same, but would look much nicer overall. 



When it comes to counting machine damage on errors, although you want problem-free coins, counting machine damage is so common that it is generally accepted to be present on most errors, and often is never even mentioned in descriptions. Therefore, the key is to buy them only when the damage is in an inconspicuous place or is minimal, although I would add that if you are buying a particularly rare error, you may have to live with more noticeable damage simply because the error type is so hard to find that your chances of finding another are slim to none. An example would be a quarter on dime double denomination 35-cent piece. This is a very rare double denomination, and finding one in almost any condition is very difficult, and so you might wish to pick up the first one you are able to locate, and then down the road “move up” in grade should you find another. Whatever condition the coin is in, make sure you are happy with how it looks, because if that scratch or that carbon spot bothers you now, it will certainly bother you later as well!

delaware quarter curved clip

Grading errors is a somewhat controversial topic, with disagreement on what should be included when deciding the grade, and also on what constitutes a certain grade. Many of the factors used to grade normal coins simply do not apply when grading errors; graders often have difficulty distinguishing the error’s individual characteristics from what they presume to be damage, weak strike, etc., and so the grade one grader might give a coin is liable to be drastically different from the grade another, more knowledgeable grader would assign. No matter the assigned grade, to most error collectors, the numerical grade is not very important, and it is recommended that you think of the grades in general terms, and buy coins from a range of grades rather than choosing one condition for all your errors. For example, an error which grades MS-66 will look much better than an MS-62 most of the time, but there probably is little or no difference between an MS-63 and an MS-64, since grading is so subjective. So if you are picky about having higher grades on your errors, rather than trying to buy coins with an MS-67’s look, don’t ignore coins graded MS-65 or MS-66, because the MS-65 or MS-66 could easily be just as nice as the MS-67. On the other hand, if you just want decent mint-state coins in the MS-63/64 range, you might buy coins which grade MS-61 to MS-64, because the MS-62 could be just as nice as the MS-63 or MS-64, or the other way around. Summed up, when it comes to errors, the saying is even more true than with “normal” coins: “Buy the coin, not the holder,” and also pay more attention to the eye-appeal of the error than on the assigned a grade.


The tools required for assembling your error type set are not extensive. One suggestion is that you print out a checklist of all the error types which you wish to put in your collection. This will help you stay on track and give you a plan for buying the coins when you attend coin shows, or are simply browsing eBay or coin websites. Mike Diamond has put together an excellent list of all the known error types, and I would be happy to e-mail you the list, upon request. Simply e-mail me at: [email protected] You may want to add to the list a few combination errors or other errors or take off some of the error which you find a bit redundant, but be careful about adding too many “extra” coins to the list, because just trying to acquire all the coins on this list will take a considerable amount of searching and effort! Also, the list is not complete, but does show a massive number of error types and also variety types. It is possible to get more minute, and include more errors, or to create different definitions of an error type that is a larger size or is a different shape or position. But this list has essentially all known error types on U.S. and foreign coins.


Most of the other tools necessary for building a type set are already familiar to the majority of numismatists, such as having a high quality loupe, inert coin holders for storage, as well as having a gram scale and micrometer for determining authenticity. Buying from a reputable dealer should virtually eliminate the problem of authenticity; however, no one is incapable of making a mistake, and so double-checking is always a good idea.

1980 nickel on cent planchet off-metal

If you are not good at authenticating coins, it is recommended that when buying expensive errors, you stick with coins certified by NGC or PCGS. Other grading services can also do a good job, but, in my experience, they have an uneven track record for certifying fakes as genuine and also, as is far more often the case, simply improperly identifying errors. If you are buying a variety, such as a doubled die, frankly none of the grading services are very reliable, and I highly recommend you attribute the variety yourself, or buy from a dealer or collector who double-checks attributions on the coins they sale. I am not saying there aren’t some very knowledgeable and competent individuals attributing varieties for some of the services, but there are also some that aren’t, and I have seen countless misattributions from all the services. Also remember that when buying certified coins, the holders can only hold 25 or so characters, so even if the holder says a coin is a certain error type, it is a good idea to ask the error dealer for a more detailed description of the coin, because there may be 5 different errors on the coin but the holder tag only has room to mention 2 or 3 of them.


In future articles on this same topic, I will be discussing what to look for in each error type--what’s desirable and what is not--as well as discussing coins in my own error type set. If you have any comments or suggestions about building an error type set, or simply have a question, please don’t hesitate to send me an e-mail at: [email protected]



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