Definition of DMPL
DMPL stands for Deep Mirror Proof-Like, and is a term usually reserved for describing certain Morgan Dollars that were struck for circulation but have unusually clean mirror fields and often frosty devices, similar to a genuine Proof coin. The DMPL Morgan is contrasted with the Prooflike (PL) Morgan which also has mirror fields, but to a lesser extent.
How Were DMPL Morgan Dollars Made
Unlike proof Morgan dollars that were made with polished planchets, specially prepared coin dies and were struck two or more times to bring out the detail, these coins were made with circulation quality planchets and struck only once.
Proof coin dies usually 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 impart 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 fresh dies were loaded into the coining press the first few coins to come off the press had the deep mirrored fields and frosted devices. As the metal of the die made its impression on the planchets, the friction of the metal against the metal of the planchet would start to wear away the mirror-like surface of the die would start to deteriorate.
The next number of 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 totally worn away.
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 "Prooflike."
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. Place the ruler on the table underneath the desklamp. 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.
DMPL is sometimes pronounced "Dimple."
Deep Mirror Proof-Like, DPL, Deep Proof Like
DMPL Morgan Dollars are most common early in the series, and were the first coins struck from new dies.
Edited by: James Bucki