Stamps the Making

Engraving and Printing
Bureau of, agency of the U.S. Treasury Department, established by the Appropriation Act of 1869. Actual printing of currency notes by Treasury employees began in 1863.
The bureau designs, engraves, and prints U.S. paper currency; Treasury bonds, bills, notes, and certificates of indebtedness; U.S. postage, customs, and revenue stamps; and engraved items for the various departments and agencies of the federal government.

All U.S. currency notes are printed from plates made from hand-tooled steel engravings; this type of printing is known as intaglio, the most difficult process to produce and to counterfeit. Annually, paper currency with a face value of more than $35 billion is printed, averaging about 16 million notes a day.
The bureau began producing U.S. postage stamps in 1894; previously the work had been done by private firms under government contract.

Watermark
Watermark, term for a figure or design incorporated into paper during its manufacture and appearing lighter than the rest of the sheet when viewed in transmitted light. Watermarks first appeared on papers produced in Italy around 1270, less than 100 years after the art of papermaking was introduced to Europe by Muslims from the Middle East.

The watermark was made when the semifluid paper pulp (mixture of cotton or other fibers) was being drained on a grid of laid (warp) and chain (woof) wires. Fine wires forming the desired design were tied on top of the grid and impressed into the pulp. This impression made the paper thinner, and therefore, more transparent, where it appeared.

Early in the 19th century, papermakers began to solder the watermark wires to the grid frame, thus insuring uniformity of impression and aiding in the detection of counterfeiting and forgery. The first British postage stamps of 1840 bore a watermark, but stamps of the United States were not so marked until 1895. When paper began to be machine-made, the watermark wiring was simply transferred to the grid cover of the dandy roll, a turning cylinder that passed over the paper.