The focus of this article is intermediate size back plate serial number 1597 on $10 1950A, B, and C FRNs, a variety that few people know about because nothing much has been written about it.
Decades ago, someone pointed out 1597 on the back of a $10 Federal Reserve note from the 1950 series. Here is what I learned about it.
The notes bearing the variety were printed from an 18-subject flat plate. Those were the last plates used to print notes on wetted paper. Consequently, the notes bearing the
