The Numismatic Bibliomania Society



The E-Sylum: Volume 17, Number 52, December 21, 2014, Article 13


We missed this one last week! On December 12, 2014 Fine Books Magazine published an article on an amazing discovery in the vaults of the Delaware Country Institute of Science. -Editor

Franklin's Nature Printing block Three extremely rare 18th-century type-metal blocks on deposit with the Library Company of Philadelphia have been identified as the instruments used to print colonial currency in Delaware and beyond. Furthermore, the blocks were the output of Benjamin Franklin's printing office and represent a technological innovation—perhaps Franklin's only real invention of a technical advance in printing—only now fully understood for the first time.

Among the most intriguing of all early American graphics are the delicate images of leaves used as a counterfeit deterrent on paper money printed by Franklin and his successors from 1737 to 1785. Experts believed they were made by pressing a leaf into plaster and making a mold of the impression that could then be used to cast printing blocks from type metal. This was guesswork, however, as the process was highly secret, and none of the blocks was known to have survived—until now. It is very rare to find examples of early American metal type, as it was normally melted down when it wore out. Type-metal blocks used to print pictures and ornaments are even rarer.

Franklin nature print note DE-05-31-60-40s.rev The Delaware Country Institute of Science (DCIS) in Media, PA, recently found what appeared to be one of the leaf blocks used to print currency in their collection, along with two metal ornament blocks and some pieces of paper money. They showed them to Jessica Linker, a current Library Company fellow, who suggested that the blocks be shown to Library Company Librarian James Green, the nation's foremost expert on Benjamin Franklin's job-printing work.

Using some very high resolution digital photography, and matching the blocks to currency in the collections of Winterthur and the American Antiquarian Society, as well as that from DCIS, Linker and Green determined that all the blocks were—in fact—cast, making possible some of their more intricate devices, such as variable surface height so that some low-relief areas print as gray—rather than the firm black of the higher relief elements and the white of recessed areas—and cross-hatching scored into the lead after casting.

All these variously complicated techniques were meant to further deter counterfeiters, on the assumption that printers trained in the normal way would not have known how to replicate them. They were effective precisely because they were made in unconventional ways. Given the date of currency printed with the leaf block, issued by the province of Delaware in 1760, this particular block was almost certainly cast not by Franklin but by his successor David Hall. Nonetheless, these blocks may be the earliest surviving pieces of type metal cast from molds made in America.

The Delaware County Institute of Science has graciously agreed to place these materials on long-term deposit at the Library Company, and we anticipate that more investigation will yield more discoveries.

For illustration purposes, I added an image of a 1760 Delaware note from the Notre Dame colonial currency site. I also reached out to colonial currency researcher Eric P. Newman for comment. -Editor

Eric Newman writes:

"Very interesting. I'll have to study it further to see how it dovetails with my previous writing on the subject of Franklin's development of nature printing."

I wasn't able to quickly locate images of notes that visibly match the printing plates, but I'll look forward to future articles exploring this connection. What a marvelous find! Who will be the first E-Sylum reader to visit the Library Company and view the blocks in person? -Editor

For more on Delaware 1760 currency, see:
Delaware Currency May 31, 1760 (

To read the complete article, see:
Benjamin Franklin Printing Blocks Identified (

Wayne Homren, Editor

NBS ( Web

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