I'm not really into collecting modern coinage but I knew I had read something on this a while back. I looked around and found the site and with permission from Patrick Glassford here is his information on them.
" German Prefab Type Varieties
Types that occur due to variations (errors) that occur during the creation of the Planchet
or the Striking of coinage, concerning the German Prefab Type Planchet.
There is a German prefab Two dollar planchet, which was used before the present method of a separate core and ring being fed to the dies. What is interesting here is that neither the core, or the inner ring were upset prior to its assembly. These types of planchets would probably be more stressful to dies and they would cause the dies to deteriorate faster. If you note on any Two dollar coin there is a raised border around the core. On the prefab planchets the dies had to form that border with out the assistance of the upset type core and ring.
It is interesting to note that all Two dollar blanks examined, have been Burnished.
Burnishing is a process that involves tumbling the planchets in a large drum with small metal pellets. This roughens or dimples the entire surface of the planchet and is helpful in producing the Frosted Cameo-like appearance of the Polar Bear on the struck coin.
Burnished planchets also "slide around" easier and are less likely to get stuck or stick together and cause other problems, like striking errors...
Having the opportunity to examine many of the German made planchets and the two piece Core and Ring sets produced by the Royal Canadian Mint (RCM), there are remarkable differences in the Burnishing.
The pieces made by the RCM have a much more pronounced and deeper Burnishing.
The RCM Pieces also appear to be very finely "oiled."
Simply put, the German Type Planchet does not have anywhere near the "shine" to those by the RCM does.
They appear "Dry" as they do not appear to be finely "oiled."
We hope to have more information soon regarding oiled planchets.
Quite few German made blanks have appeared, but that supply will dry out as the prefab type of
planchet was phased out in the early part of 1996.
In time it could be a key piece in completing a set of Planchets. *Estimated value $150.00* "
Cheers, Bill
