In order to understand how die varieties such as doubled dies, repunched mint marks (RPMs ), over mint marks (OMMs), repunched dates (RPDs), overdates (OVDs), and misplaced dates (MPDs) are produced, we need to have a working knowledge of how the dies which are used to strike coins are made. All of the variety types noted here are die errors. This means that the error is on the die itself.

A die is a steel rod with a face that is the same size as the coins that it will be striking. This steel rod will contain the design for one side of the coin. Two of these steel rods (dies) are needed to strike coins. One will have the obverse (front) design and the other will have the reverse (back) design.

The dies are set up in a machine called a coin- ing press so that a planchet (blank) will come be- tween them. In the older coining presses, one die would be positioned above the other. The upper die (ham- mer die) would come down with great force and strike the planchet while it was resting on the lower die (an- vil die). The force of the upper die striking the planchet on the lower die would place the images from the dies onto the planchet and the result would be a coin as we know it.

There is often a great deal of misunderstand- ing by those unfamiliar with die varieties as to how they are produced. Many collectors think that die va- rieties are produced as the coins are being struck. In the case of doubled dies, a frequent misconception is that they are produced when coins are struck twice by the dies. This is not the case, as we will soon see. Coins made for circulation are struck only once. Only proof coins are struck twice and, even there, that is not the cause of any doubled dies that might be found on Droof coins.

The truth is that all die varieties, including 4 The HIJR

doubled dies, are the result. of mishaps that occur in the process of making the dies. As we explore the die making process, we will see how the various die vari- eties resulted over the years. Modern mint technol- ogy for the die making process has now removed the likelihood that the die varieties we enjoy collecting will ever be produced again.

In this installment, we will give you an over- view of the die making process. In the months ahead, we will look at each step along the way and we will see the point in the process at which the various types of varieties can occur.

The whole process of making dies traces back to the designing of the image we see on the coins. Once a coin design has been submitted and approved, a mint engraver will make a three-dimensional model in clay. Only the central part of this design appears on this clay model. Plaster is then poured over the clay model. The result is a plaster model with the design incused or indented.

Today the lettering that we see around the rim, as well as the full date, are engraved into this plaster negative. Up until the mid-eighties, only the first two digits of the date were engraved into the plaster nega- tive. In the nineteenth century the lettering around the rim was added at a later point in the die making pro- cess. Dates and mint marks were also added at differ- ent points in the die making process. We will examine

M9VnIIne 2()()4