DMPL (pronounced "dimple") is an abbreviation that stands for Deep Mirror Proof-Like. This term is usually reserved for describing Morgan Dollars that were struck for circulation but had unusually clean mirror-like fields and frosted devices that are very similar to a Proof coin. The DMPL Morgan is contrasted with the Proof-Like (PL) Morgan, which also has mirror fields but the devices are not deeply frosted as what you would find on the DMPL.
How Were DMPL Morgan Dollars Made
Unlike Proof Morgan dollars that were made with polished planchets, specially prepared coin dies and was struck two or more times to bring out the finer details, these coins were made with circulation quality planchets and struck only once. Proof coin dies are prepared with greater detail to showcase the design of the coin. Multiple strikings bring up the finer detail on proof coins.
DMPL Morgan dollars used coin dies that were initially made from a master hub that imparted the design into the die. The dies were then polished or basined to give a mirrored surface on the field of the die. When these dies were used to strike coins, it resulted in a mirrored like surface in the field and a frosted surface on the devices. This imparted a cameo contrast between the field and the devices on the coin. However, the planchets were not polished before striking, and the coins were only struck once.
When new dies were loaded into the coining press, the first few coins to come off the press had the deeply-mirrored fields and frosted devices. As the metal of the coin die made its impression on the planchets, the friction of the metal of the coin die being pressed into the metal of the planchet would start to deteriorate the mirror-like surface of the die. The next twenty to thirty coins would have a semi-mirrored surface in the field. These are known as Proof-Like or PL. Eventually, the mirror-like qualities of the die would be worn away.
Experts agree that if there is a significant difference in value between a DMPL and PL designation for a particular coin, you are advised to purchase one in a recognized third-party grading service slab. This will guarantee the authenticity of the coin and that the coin was not doctored to emulate the Proof-Like surfaces.
How to Determine DMPL
The way to determine whether or not your Morgan Dollar is PL or a DMPL is to measure the amount of reflectivity on the mirror surface. Most grading services use both the PL and DMPL designations on their slab labels. Usually, you'll see the term Semi-Prooflike (SPL) used to describe Morgan Dollars that don't quite qualify as full "Proof-Like."
The easiest way to determine if your Morgan Dollar is Deep Mirrored Proof-Like, Proof-Like or neither, is to use a ruler and a desk lamp. make sure you use a white rule with black lettering and numbers. If you use a clear ruler you will not be able to get an accurate measurement of the distance. Place the ruler on the table underneath the desk lamp. Hold the coin on its edge on the table next to the beginning of the ruler. If you can clearly see 2 to 4 inches reflected in the field of the coin, this will receive the Proof-Like designation. If you can clearly see between 6 and 8 inches of the ruler, this would receive the Deep Mirrored Proof-Like designation.
The distance between 4 and 6 inches, which is not covered in the above scale, comes onto a matter of judgment. For a coin to receive the DMPL designation, the devices on both sides of the coin must have a high degree of cameo contrast. Therefore if the mirrored surface of the coin allows you to see clearly between 4 and 6 inches and the devices are deeply frosted, this coin would receive the DMPL designation.
If the mirror-like fields of the coin allow for reflectivity between 4 in 6 inches and the devices are not heavily frosted, this coin would receive a Proof-Like designation. However, this is subjective and takes into the overall eye appeal of the coin. A coin with great eye appeal and deep cameo contrast frosted devices would definitely receive a DMPL designation.
DMPL is sometimes pronounced "Dimple."
Deep Mirror Proof-Like, DPL, Deep Proof Like
Edited by: James Bucki